Here's one way that online networking is kind of like a kidnapping. If you can't find a reason to work together with someone and follow up on a networking connection in the first 48 hours after a LinkedIn connection, I'd bet your chances of ever making that connection productive significantly drop off. I know a lot of bloggers and other random online connections that I got really excited about at first, chatted for a bit, connected with on LinkedIn, and then never really did anything with.
LinkedIn needs a way to build in not only more specific follow up, but also drop a few hints. If I'm looking for a front end developer, and I connect to you, if your best friend does exactly what I need, it should alert the two of us that there's a connection to be made. Similarly, a "things I can do for other people" page would be nice. It's not enough to float job requests around that say "Do you know anyone for this?" LinkedIn already knows the answer to that. How about you tell me who I know for that job and save me the trouble!?
The other thing that would be interesting would be some kind of reciprocity score. The same way it gives me a score on how complete a profile I have, it should tell me the +/- of how often I ask for something from the system versus how often I provide something to it. Perhaps I don't make enough recommendations, but shouldn't I get credit for the number of nodes I've added to the system?