Script for opening web inspector window for remote debugging iOS web apps (including phonegap and other webview apps). This version of the script will suspend and wait for 30 seconds for Safari to establish a connection with the device (or simulator) and open the web inspector window as soon as technically possible.

open-webinspector.applescript

#!/usr/bin/osascript

# Name of the device as visible in Safari->Develop menu
set deviceName to "iPhone Simulator"

# Number of seconds to wait for the simulator window to show up
set maxWait to 30

# ---------------------------------------
# You shouldn't modify anything below here
set hasClicked to false
set x to 0
tell application "Safari"
        activate
        repeat until hasClicked or x > (maxWait * 10)
                try
                        tell application "System Events"
                                click menu item "index.html" of menu deviceName of menu item deviceName of menu "Develop" of menu bar item $item "Develop" of menu bar 1 of application process "Safari"
                        end tell
                        set hasClicked to true
                on error foo
                        delay 0.1
                        set x to x + 1
                end try
        end repeat
        if hasClicked = false then
                display dialog "Unable to connect to iOS simulator - make sure that it's working" buttons {"OK"} default button 1
        else
                try
                        tell application "System Events"
                                click button 1 of window "Top Sites" of application process "Safari"
                        end tell
                end try
                return
        end if
end tell

This is awesome, been looking for something like this for a while.

So just to summarize all the edits for Yosemite, here's the updated script.

Thanks to @Thinkscape, @jfrumar and @raztus 😄

#!/usr/bin/osascript

# Name of the device as visible in Safari->Develop menu
set deviceName to "iOS Simulator"

# Number of seconds to wait for the simulator window to show up
set maxWait to 30

# ---------------------------------------
# You shouldn't modify anything below here
set hasClicked to false
set x to 0
tell application "Safari"
    activate
    repeat until hasClicked or x > (maxWait * 10)
        try
            tell application "System Events"
                click menu item "index.html" of menu deviceName of menu item deviceName of menu "Develop" of menu bar item "Develop" of menu bar 1 of application process "Safari"
            end tell
            set hasClicked to true
        on error foo
            delay 0.1
            set x to x + 1
        end try
    end repeat
    if hasClicked = false then
        display dialog "Unable to connect to iOS simulator - make sure that it's working" buttons {"OK"} default button 1
    else
        try
            tell application "System Events"
                click button 1 of window "Favorites" of application process "Safari"
            end tell
        end try
        return
    end if
end tell

Thanks everyone!

I made a fork of this to both compile and run the debugger, and also made instructions on how to assign it to a shortcut key with Automator.
https://gist.github.com/uniphonic/fc4e679884aa83787c26

Made a fork of @uniphonic's fork above, for iTerm - https://gist.github.com/benallfree/948994ad6b143b5566f2

Here is my version of opening Safari Web Inspector - https://gist.github.com/14ea36ce3bc9cc5632b78252fe35ec76

It must works for debugging of real iPad webview without emulator? I see Unable to connect to iOS simulator

I made an Alfred workflow for this. - https://github.com/alphacat2018/AlfredOpenSafariInspector

If you can't get @alphacat2018's suggestion to work, try using this other Workflow with Alfred:
https://github.com/dcalhoun/alfred-remote-inspector-workflow