Hootsuite is a twitter client that simplifies the tweet process for multiple accounts. It allows you to monitor your brand, customize your twitter experience and if schedule your tweets.
Hootsuite integrates well with ping.fm (which I’m a big fan of) and has its’ own shortened URL. My favorite features of the Hootsuite twitter client is the usage and metrics. The dashboard is a wealth of visualizations link statistics. Graphs show not only a summary but also individual message statistics, a bonus for your break out tweets. Last and certainly not least is the team collaboration ability allowing multiple people access to one social account through Hootsuite tools.
Hootsuite received 1.9M in series A funding last December (2009) from Hearst Interactive Media and Blumberg Capital with other prominent angel investors involved like Social Concepts, and Geoff Entress.