I'd like to announce Scallion, an OpenCL vanity .onion address generator. It gets around 600MH/s on a 6870 (similar on a 5770), allowing it to generate an 8-character prefix in just 15 minutes on average. It's written in C# and runs in both Linux (on Mono) and Windows.

Update (23 Nov 2013): I'm now generating vanity .onion addresses for a small fee. See the Scallion as a Service documentation for more details. In particular, 7 and 8 character .onion addresses are free if you send me a dirty limerick featuring Tor in some way. Contact me through the email given above or with a PM here.

I mentioned this in a thread over in off-topic, but that's not really the right spot for a project announcement.

Features:
1) Blindingly fast - 600MH/s vs. 2MH/s for shallot
2) Performs PKCS #1 v2.1 sanity checks via openssl's RSA_check_key function
3) FOSS - MIT licence
4) Support for 1024, 2048, or 4096 bit keys
5) Estimates time required to generate a key (on average)

Check out the Github page: http://www.github.com/lachesis/scallion
or skip straight to the binaries: https://github.com/downloads/lachesis/scallion/scallion-v0.9.zip

If you have any problems, reply to this thread or open an issue on github.

Donations: 1onion1PNeM2x9LhdqWn6uVFyU2iSpy7M