Service pimpery
1) Akismet — I’ve been using it to stop wordpress and trac spam for the past ~3 months, and I only just remembered that it exists, since it let one through (as opposed to the 20 a day I was getting before)
2) OpenID; which has been around a while, but might actually get somewhere now that microsoft have said they’ll be putting their weight behind it (although they may well end up doing their embrace / extend / extinguish thing…)
I shall add support for them to my webapps once I find APIs and time…