Browser based twitter client that supports multiple twitter accounts

Use oAuth or HTTP auth to login
Attach a bit.ly account to each twitter account so you can have different bit.ly analytics for each account. Helps you track click-thrus on your links by account.
Supports posting updates to WordPress, tumblr and other sites that emulate the full twitter API. At the moment WordPress and tumblr do not support the full twitter API.
Each account can have a geo position associated with it so that when you choose to post an update to that account the geo information will automatically be posted with the update.