Create a service workflow in Automator with a "Run AppleScript" action with this for an easy shortcut for posting to pastebin.com (See http://marc-abramowitz.com/archives/2011/01/02/os-x-service-for-posting-text-to-pastebin-com/)

pastebin.workflow.applescript

-- pastebin.workflow.applescript
--
-- An automator workflow to copy selected text to pastebin.com
--
-- Created by Marc Abramowitz
-- December 5, 2010
-- version 1.0

on run {input}
	
	-- prep input for validation
	set inputResult to (input as string)
	
	-- Build the curl command to post to pastebin.com
	set curlCMD to "curl --stderr /dev/null -d\"paste_code=" & urlencode(inputResult) & "\" http://pastebin.com/api_public.php"
	
	-- Run the script and get the result:
	set pastebinUrl to (do shell script curlCMD)
	
	-- Open in default web browser
	open location pastebinUrl
	
	-- return result to be copied to the clipboard
	return pastebinUrl
	
end run

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

This is described a bit more at http://marc-abramowitz.com/archives/2011/01/02/os-x-service-for-posting-text-to-pastebin-com/

This is now obselete.
"THIS API HAS BEEN DISABLED. Please use Pastebin's new API. http://pastebin.com/api"