Wow, I haven't been paying attention or else am totally oblivious to what i read. I don't remember LJ auto-linking URL's in the past. Can anyone tell me when that went into effect? I just tried with the web client and it does it too so it's not the win32 client at least. :P What if you want to post an URL and not have it linked? :P
Update: Apparently this came into effect way back on 2001-04-28 according to the changelog. Feh.