A few ways to get more productive using your cell phone:

Jott – send yourself a message that will be forwarded to your Inbox
Pinger – send a voice mail to others without the need to call and speak to them
30 boxes – the online calendar on your cell
Stikkit – an organization app
GoogleSMS – kind of speaks for itself
Gubb – add items to a “to do list” by a simple text message
Twitter – online community with instant messaging also available through your cell…