I was working on converting this very same script this morning, so I thought I'd better come and check I wasn't reinventing the wheel. And low and behold I find this post.
I converted David Ferguson's Wolfram|Alpha extension to a workflow (and made some tweaks along the way )
It requires you have an AppID of your own (get one here). Note: Make sure you wait a few minutes before entering the code; Wolfram|Alpha's servers seem to take a moment to register the AppID.
It provides feedback with the answer and input interpretation. If you action an item, it will output all the available information to Growl. Pressing ⌥↩ will copy the answer to the clipboard; ⌘↩ will open your query in Wolfram|Alpha (in the default browser).
Here's a picture of the workflow editor:
Here's what it looks like in action:
Hope you like it!
Download Here
Update (May 15, 2013): Fixed another bug that prevented saving of AppID
Update (March 5, 2013): Fixed bug that prevented the workflow from saving AppID on certain setups
Update (Feb 25, 2013): Fixed garbled text issues, added 'Selection is OS X' argument to hotkey
panrubius got a reaction from Tyler Eich in Wolfram|Alpha workflow
