This one's a little experimental, but it's so intriguing--and the potential applications so "wow"--that I have to share it. An experimental application, called Cellphedia, developed by a New York University student, lets users type a question into a cell phone, post it for all registered users to see, then lets others compete to answer it.
OK, so what, you say? Well, this is just the first, embryonic version. Ultimately, it could become a mobile wiki, or collaborative journal or encyclopedia that harnesses the knowledge of all who go there. So instead of "mob-logging" (people joining forces when prompted via cell) you have "mob-wiki," people sharing their intelligence from the palm (or Palm) of their hand. The inventor, in fact, notes that Wikipedia was his main inspiration.
Imagine the applications: Your mobile sales force learns something of relevance to others on the team and sends it around for all those on the road to see on their mobile devices. Or they have a question and can get an immediate answer in a meeting, without using a computer or calling anyone. In fact they may not even know who else has the knowledge but can just tap the entire group, around the world. You offer your expertise and can give it, from anywhere, for a fee that could ultimately be linked automatically to some sort of payment system. A cell phone service provider (your business?) becomes the intermediary, letting people pay a minute amount to connect and share valuable information (the Skype model, kind of).
I've done a little imagining out loud here, but I wanted to let you have a peek and consider the possibilities.