I know I read about this on reddit within the last week or so… But I just can’t find it! My Google-fu is failing me! Grrrrr. There was a general upload text area form where you copy in your code snippet. You then select the language from a drop down, and click submit. In the commentary on reddit about this service, the author talked about all the things he did to keep his machines safe from attack, including using virtual machines, code jails, and refreshing both the host and the VMs frequently. I can remember a bunch of keywords from the comments, but apparently there is no comment search at reddit! (And a google search with “site:reddit.com” didn’t work either.) If you remember seeing this, too, let me know!

Update: Thank you, Internets! Codepad.org is the answer. (Though UtilityMill.com looks similar, too.) Here’s the original thread on reddit that I was looking for, too.