Slandr Mobile Twitter
It it great cause it does all the stuff that m.twitter.com and twitstat do not (all) do:
* it is pure HTML, no slow Java app or so.
* it remembers your login (failed once today, we'll see)
* it has a replies tab
* it has a reply-button
* it has direct message tab
* it shows you ppl/twittereres in 3, 5, 10 and 20 miles radius (ok, miles, but .. - I subscribed to 5 twitterers in my area I had not 'seen' before)
* it lets you subscribe and unsub to ppl by pressing a micro-icon
* it displays well on the treo 650 (which hahlo does not do ;( )
Right now I hit a rate limit, but I had twhirl on and used some other services to do stats of twitter.
Check out slandr, it's cool ;) (And no I am not affiliated with them and had now contact up to now.)
PS: and I think Twitter should buy Slandr ;) Their page is as m.twitter.com SHOULD be ;)