set the ClipURL to (the clipboard as string)

	ignoring case
		if ((characters 1 through 4 of ClipURL as string) is not "http") then
			return "Malformed URL."
		else
  		set the EncodedClipURL to urlencode(ClipURL) of me
			set curlCMD to ¬
				"curl --stderr /dev/null \"http://bit.ly/api?url=" & EncodedClipURL & "&login=[your_username]&apiKey=[your_API_key]\""

			-- Run the script and get the result:
			set tinyURL to (do shell script curlCMD)

			return tinyURL
		end if
	end ignoring


on urlencode(theText)
	set theTextEnc to ""
	repeat with eachChar in characters of theText
		set useChar to eachChar
		set eachCharNum to ASCII number of eachChar
		if eachCharNum = 32 then
			set useChar to "+"
		else if (eachCharNum ≠ 42) and (eachCharNum ≠ 95) and (eachCharNum < 45 or eachCharNum > 46) and (eachCharNum < 48 or eachCharNum > 57) and (eachCharNum < 65 or eachCharNum > 90) and (eachCharNum < 97 or eachCharNum > 122) then
			set firstDig to round (eachCharNum / 16) rounding down
			set secondDig to eachCharNum mod 16
			if firstDig > 9 then
				set aNum to firstDig + 55
				set firstDig to ASCII character aNum
			end if
			if secondDig > 9 then
				set aNum to secondDig + 55
				set secondDig to ASCII character aNum
			end if
			set numHex to ("%" & (firstDig as string) & (secondDig as string)) as string
			set useChar to numHex
		end if
		set theTextEnc to theTextEnc & useChar as string
	end repeat
	return theTextEnc
end urlencode

set the ClipURL to (the clipboard as string)

	ignoring case
		if ((characters 1 through 4 of ClipURL as string) is not "http") then
			return "Malformed URL."
		else
  		set the EncodedClipURL to urlencode(ClipURL) of me
			set curlCMD to ¬
				"curl --stderr /dev/null \"http://bit.ly/api?url=" & EncodedClipURL & "&login=[your_username]&apiKey=[your_API_key]\""

			-- Run the script and get the result:
			set tinyURL to (do shell script curlCMD)

			return tinyURL
		end if
	end ignoring


on urlencode(theText)
	set theTextEnc to ""
	repeat with eachChar in characters of theText
		set useChar to eachChar
		set eachCharNum to ASCII number of eachChar
		if eachCharNum = 32 then
			set useChar to "+"
		else if (eachCharNum � 42) and (eachCharNum � 95) and (eachCharNum < 45 or eachCharNum > 46) and (eachCharNum < 48 or eachCharNum > 57) and (eachCharNum < 65 or eachCharNum > 90) and (eachCharNum < 97 or eachCharNum > 122) then
			set firstDig to round (eachCharNum / 16) rounding down
			set secondDig to eachCharNum mod 16
			if firstDig > 9 then
				set aNum to firstDig + 55
				set firstDig to ASCII character aNum
			end if
			if secondDig > 9 then
				set aNum to secondDig + 55
				set secondDig to ASCII character aNum
			end if
			set numHex to ("%" & (firstDig as string) & (secondDig as string)) as string
			set useChar to numHex
		end if
		set theTextEnc to theTextEnc & useChar as string
	end repeat
	return theTextEnc
end urlencode

set the ClipURL to (the clipboard as string)

	ignoring case
		if ((characters 1 through 4 of ClipURL as string) is not "http") then
			return "Malformed URL."
		else
  		set the EncodedClipURL to urlencode(ClipURL) of me
			set curlCMD to ¬
				"curl --stderr /dev/null \"http://bit.ly/api?url=" & EncodedClipURL & "&login=[your_username]&apiKey=[your_API_key]\""

			-- Run the script and get the result:
			set tinyURL to (do shell script curlCMD)

			return tinyURL
		end if
	end ignoring


on urlencode(theText)
	set theTextEnc to ""
	repeat with eachChar in characters of theText
		set useChar to eachChar
		set eachCharNum to ASCII number of eachChar
		if eachCharNum = 32 then
			set useChar to "+"
		else if (eachCharNum ≠ 42) and (eachCharNum ≠ 95) and (eachCharNum < 45 or eachCharNum > 46) and (eachCharNum < 48 or eachCharNum > 57) and (eachCharNum < 65 or eachCharNum > 90) and (eachCharNum < 97 or eachCharNum > 122) then
			set firstDig to round (eachCharNum / 16) rounding down
			set secondDig to eachCharNum mod 16
			if firstDig > 9 then
				set aNum to firstDig + 55
				set firstDig to ASCII character aNum
			end if
			if secondDig > 9 then
				set aNum to secondDig + 55
				set secondDig to ASCII character aNum
			end if
			set numHex to ("%" & (firstDig as string) & (secondDig as string)) as string
			set useChar to numHex
		end if
		set theTextEnc to theTextEnc & useChar as string
	end repeat
	return theTextEnc
end urlencode

TextExpander is a great Mac tool that expands special abbreviations typed anywhere in the OS into useful snippets of text. One of the AppleScript snippets included shortens a URL in the clipboard using the bit.ly URL-shortening service. You copy the URL from your browser and just type /bitly in an email, IM, or Twitter, for example, and the abbreviation is replaced by a shortened URL.

One advantage of bit.ly over other shortening services is that it provides click statistics  and other useful information for each shortened URL. If you have a (free) bit.ly account, the URLs you shorten are easily accessed through their site. However, the script included with TextExpander shortens the URL without associating it with your bit.ly account. _This_ version of the script is a very simple modification which associates URLs you shorten with your bit.ly account. 

To use this script, change `[your_username]` and `[your_API_key]` in line 9 to the correct values. (Once you have created a bit.ly account, you can find your API key here: [http://bit.ly/app/developers](http://bit.ly/app/developers).) Create a new snippet in TextExpander and paste the script into the Content field, making sure to select AppleScript in the dropdown above the field. Set the abbreviation and you're done.

bit.ly URL-shortening script for TextExpander that associates URLs with your bit.ly account

url

ActionScript 3