If you use Twitter [my twitter page] and want to send tweets from within Second Life then you're a little spoiled for choice in terms of clients you can choose from, but if like me, you're happy with your gadgets being a little rough and ready if they're powerful, then you'll love Squawk by Vincent Shore. Right now there aren't even any instructions, but it'll be simple to figure out for most SL'ers (IM me if you need a hand). The client is configurable, and really simple to use and according to Vincent, there are big plans ahead for the Squawk client in terms of community, additional API/Service integration and paid features.
I managed to catch up with Vincent in the week and talk to him about his plans for the client, which by the way, you can find here [SLUrl].
The first thing that's apparent about Squawk is that it's not simply another Twitter gateway, there's a Website which aggregates Squawk users tweets on the home page, but also most popular places the client is being used from (currently that's Dr.Dobb's Island where I've been using it as a note taking tool during the Life 2.0 convention)
Among the plans for the future is Del.icio.us integration, giving Squawk a kind of crowd sourced popular places functionality similar to Sloog and also Digg in terms of voting. Some additional functionality does require a small payment, such as receiving tweets inworld (something i turned off pretty quickly..) and it's not clear yet how future additions ot the client will be billed.
If you're a Twitter / SL power user. I recommend you check out Squawk, and also that you join our bi weekly Twitter users meet today at 8am SLT - the group is fun and friendly and full of geeks, what more could you possibly ask for?