I have been waiting for ages for a decent browser based Twitter app, and lo and behold Seesmic have launched one today. Mashable have done a fairly sizeable review here http://mashable.com/2009/07/10/seesmic-web/ but my twopennyworth is I like the very clever way they have made it looks like email (ulp). No, it really does works well with the Tweeter on the right (minus thumb pic) and then the message stretched across Gmail styleee. It sounds much better than it sounds.
Not sure how much I’ll use it as I have Tweetdeck installed on every PC I have and Tweetie on my iPhone, but good to have it as an option.