This is my favourite part - I find it helps if you treat it like the game it is. Meet people, ask about their business, be friendly and before you know it they are asking your advice on an app. Get in there and close the deal, do a good job, get a referral, rinse and repeat.
It's all about networking and talking a good game. It doesn't come natural to engineers I admit but once I decided to just go for it I found it can be fun.
On the plus side you do get to meet a lot of interesting people and discover interesting ideas for apps.
We're tackling (pun intended) the same problem (it's an interesting one!) but from a mobile perspective and focusing solely on Soccer.
If you have an iPhone app and fancy giving it a try, you can grab the app (free!) from http://www.ifives.net.