Kristine posted here before about wander lust – And now with MT 2.5 you can ping them. She posted the instructions here.
If you already have an account with Wander lust, and already have this in between your MT entries tag:
<!–syndicate <$MTEntryTitle$>|<$MTEntryExcerpt$> /syndicate–>
Then go to Blog Config (in MT) – go to preferences – and under "Publicity / Remote Interfaces / TrackBack" there'll be a field to enter additional pings("Others: (separate URLs with a carriage return)"). Add this:
http://wander-lust.com/pinger.cgi?your-name@your-domain.com
(where your-name@your-domain.com is the email address you used to sign up with Wander Lust)