The problem is that the .com is not available, and the owner of the .com isn't interested in selling the domain (or I'm bad at trying to negotiate it... but he didn't even seem interested in talking numbers). The .com version of the site is not being used - it currently just lists an empty directory (and has for the past 9 months or so that I've been watching it).

Am I going to regret pushing forward with the .net address, or should I try to think of some different names that end in .com?

I'm still writing software and tweaking the model quite a bit, so I'm afraid I can't really mention the domain name yet; I hope it's possible to speak about this in generalities.

I will say the target audience is more the Facebook / Youtube / Myspace crowd than it is the Slashdot / reddit / YC crowd.

[Edit: Just a quick note; if I had been able to find any .com names that were even 60% as strong as I feel the .net name is for this particular idea, I would have just grabbed it and moved on. I know de.licio.us did fine, but I just feel they were targeting much more technically savvy users than I will be.]