Over the past year I’ve collected a list of services to ping when you update your blog. Here is a list of those I have so far. There are heaps more out there – you might also like to head over to Jeremy’s Services to Ping list also where he’s got a list of 41 or so services (many duplicated here).
Please note – you might not want to ping them all every time as it can take a long time to post anything. The Pingomatic one at the top of the list automates the process and pings many services for you all at once.