do you *really* want to know who tweets around you? Maybe if you were a speaker in a conference and you want to know if the audience is listening or err tweeting ' in a conference. very bored'. .
Most of the apps i have seen so far are terribly cool. I mean it makes me go 'Wow' but if you get me an Iphone and ask me to use them, I will not. Primarily, i rarely tell the world what I do. (everyday). I mean, i find it amusing to tell my friends on a daily basis, what i do at the gym or what i had for lunch. Unless it is absolutely necessary to inform people about a certain change in your life/work or sharing a good article or video i find status updates quite silly. On the flip side, it is however addictive - to read what others are upto!! ;).
I have been travelling quite a bit over the last couple of months and each time to my amazement, as soon as the flight hits the runway people switch on their pda's/iphone/blah blah. and guess what - they login to update their status saying ' Flight sucked ' or ' In CA '. Whatever!. I find it pleasurable to travel with nothing but my 30$ you-can-only-make-calls-or-send-sms Nokia and its pitiable charger.