Find all Content Types and Lists where a particular column is used within a site collection

ColumnUsage.ps1

param (
    [String]$SiteUrl = 'http://spdev',
    [String]$FieldName = 'Title'
)

Add-PSSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue

$site = Get-SPSite $SiteUrl

"Showing where ""$FieldName"" is used"
foreach ($web in $site.AllWebs) {
    foreach ($ctype in $web.ContentTypes) {
        if ($ctype.Fields.ContainsField($FieldName)) {
            $web.Url + ' Content Type: ' + $ctype.Name
        }
    }
    foreach ($list in $web.Lists) {
        if ($list.Fields.ContainsField($FieldName)) {
            $web.Url + ' List: ' + $list.Title
        }
    }
}