socialscope, but it's not available to the public yet. ubertwitter is the best you'll find, it's not the prettiest sight but it has more features. IMO paying for a twitter app fails.
I just signed up for Twitter yesterday...I'm still fairly unsure of the point of it....but I'm giving it a shot...anyway I downloaded TinyTwitter and I really don't like it...but at the same time I have no idea if thats a fairly normal program or just a bad program seeing as...well I've never used a twitter program...
My data was not working at all on my phone and my wife was having trouble as well. I jumped on Twitter for the live search function everyone is talking about and found out there was a VZW Data outage in the area and it wasn't just my phone. That definitely got me to really like twitter. And i've been using UberTwitter on my phone which seems great.