Helper methods for registering JS / CSS dependencies, including inline blocks.

HtmlHelperExtensions.cs

using System;
using System.Collections.Generic;
using System.Text;
using System.Web.Mvc;
using System.Web.WebPages;

namespace UmbracoCms.Web
{
    public static class HtmlHelperExtensions
    {
        private const string _jsIncludesViewDataName = "RenderJavaScriptIncludes";
        private const string _jsViewDataName = "RenderJavaScript";

        private const string _cssIncludeViewDataName = "RenderStyleIncludes";
        private const string _cssViewDataName = "RenderStyle";

        public static HtmlHelper IncludeJs(this HtmlHelper htmlHelper, string key, string url)
        {
            var scriptHash = htmlHelper.ViewContext.HttpContext
              .Items[_jsIncludesViewDataName] as Dictionary<string, string>;

            if (scriptHash != null)
            {
                if (!scriptHash.ContainsKey(key))
                {
                    scriptHash.Add(key, url);
                }
            }
            else
            {
                scriptHash = new Dictionary<string, string> { { key, url } };
                htmlHelper.ViewContext.HttpContext.Items.Add(_jsIncludesViewDataName, scriptHash);
            }

            return htmlHelper;
        }

        public static HtmlHelper IncludeJs(this HtmlHelper htmlHelper, 
            Func<object, HelperResult> template, bool includeScriptTags = true)
        {
            // No key, so just give it a random one
            return htmlHelper.IncludeJs(Guid.NewGuid().ToString(), template, includeScriptTags);
        }

        public static HtmlHelper IncludeJs(this HtmlHelper htmlHelper, string key,
            Func<object, HelperResult> template, bool includeScriptTags = true)
        {
            var scriptHash = htmlHelper.ViewContext.HttpContext
              .Items[_jsViewDataName] as Dictionary<string, string>;

            var val = includeScriptTags
                ? string.Format("<script type=\"text/javascript\">{0}</script>", template(null))
                : template(null).ToString();

            if (scriptHash != null)
            {
                if (!scriptHash.ContainsKey(key))
                {
                    scriptHash.Add(key, val);
                }
            }
            else
            {
                scriptHash = new Dictionary<string, string> { { key, val } };
                htmlHelper.ViewContext.HttpContext.Items.Add(_jsViewDataName, scriptHash);
            }

            return htmlHelper;
        }

        public static MvcHtmlString RenderJsIncludes(this HtmlHelper htmlHelper)
        {
            var result = new StringBuilder();

            // Render includes
            var includesHash = htmlHelper.ViewContext.HttpContext
              .Items[_jsIncludesViewDataName] as Dictionary<string, string>;

            if (includesHash != null)
            {
                foreach (var script in includesHash.Values)
                {
                    result.AppendLine(string.Format(
                      "<script type=\"text/javascript\" src=\"{0}\"></script>",
                      script));
                }
            }

            // Render inline scripts
            var inlineHash = htmlHelper.ViewContext.HttpContext
              .Items[_jsViewDataName] as Dictionary<string, string>;

            if (inlineHash != null)
            {
                foreach (var script in inlineHash.Values)
                {
                    result.AppendLine(script);
                }
            }

            return MvcHtmlString.Create(result.ToString());
        }

        public static HtmlHelper IncludeCss(this HtmlHelper htmlHelper, string key, string url)
        {
            var scriptHash = htmlHelper.ViewContext.HttpContext
              .Items[_cssIncludeViewDataName] as Dictionary<string, string>;

            if (scriptHash != null)
            {
                if (!scriptHash.ContainsKey(key))
                {
                    scriptHash.Add(key, url);
                }
            }
            else
            {
                scriptHash = new Dictionary<string, string> { { key, url } };
                htmlHelper.ViewContext.HttpContext.Items.Add(_cssIncludeViewDataName, scriptHash);
            }

            return htmlHelper;
        }

        public static HtmlHelper IncludeCss(this HtmlHelper htmlHelper,
            Func<object, HelperResult> template, bool includeStyleTags = true)
        {
            // No key, so just give it a random one
            return htmlHelper.IncludeCss(Guid.NewGuid().ToString(), template, includeStyleTags);
        }

        public static HtmlHelper IncludeCss(this HtmlHelper htmlHelper, string key,
            Func<object, HelperResult> template, bool includeStyleTags = true)
        {
            var scriptHash = htmlHelper.ViewContext.HttpContext
              .Items[_cssViewDataName] as Dictionary<string, string>;

            var val = includeStyleTags
                ? string.Format("<style type=\"text/css\">{0}</style>", template(null))
                : template(null).ToString();

            if (scriptHash != null)
            {
                if (!scriptHash.ContainsKey(key))
                {
                    scriptHash.Add(key, val);
                }
            }
            else
            {
                scriptHash = new Dictionary<string, string> { { key, val } };
                htmlHelper.ViewContext.HttpContext.Items.Add(_cssViewDataName, scriptHash);
            }

            return htmlHelper;
        }

        public static MvcHtmlString RenderCssIncludes(this HtmlHelper htmlHelper)
        {
            var result = new StringBuilder();

            // Render includes
            var includesHash = htmlHelper.ViewContext.HttpContext
              .Items[_cssIncludeViewDataName] as Dictionary<string, string>;

            if (includesHash != null)
            {
                foreach (var css in includesHash.Values)
                {
                    result.AppendLine(string.Format(
                      "<link rel=\"stylesheet\" type=\"text/css\" href=\"/{0}\">",
                      css));
                }
            }

            // Render inline css
            var inlineHash = htmlHelper.ViewContext.HttpContext
              .Items[_cssViewDataName] as Dictionary<string, string>;

            if (inlineHash != null)
            {
                foreach (var css in inlineHash.Values)
                {
                    result.AppendLine(css);
                }
            }

            return MvcHtmlString.Create(result.ToString());
        }
    }
}

Master.cshtml

@using UmbracoCms.Web
@inherits Umbraco.Web.Mvc.UmbracoViewPage
@{
    Layout = null;
}

<!DOCTYPE html>
<html lang="en">
  <head>
    <title>@Model.Name</title>
    @Html.RenderCssIncludes()
  </head>

  <body>
    @Html.Partial("TestPartial")
    
    <!-- Javascripts -->
    @Html.RenderJsIncludes()
  </body>
</html>

TestPartial.cshtml

@using UmbracoCms.Web
@inherits Umbraco.Web.Mvc.UmbracoViewPage
@{
    Html.IncludeJs("jquery", "/scripts/jquery.min.js")
        .IncludeJs(
            @<script type="text/javascript">
                // Initi javascript here...               
            </script>, false);
}
<!-- MARKUP HERE -->