Where do I play online games with a long time control? I don't have a lot of opportunity to play serious OTB games, so I'd like to play chess online. On chess.com, though, the longest standard time control is 30 min per person, presumably there are not many players wanting to play at longer time controls there. I prefer to have more time, though.

Is there a website where there are enough people willing to play 1 to 1.5 hour (per person) games, so that you are paired within a reasonable amount of time (say, 15 minutes)? (Preferably based on online rating, of course.)
On chess.com, there are at least two groups of people interested in games with long time controls (e.g. 90'+30'' and 45'+45''): the Slow Chess League and the Slow LIVE Chess Association.

They have regular Swiss style tournaments where you have to agree on a date with your opponent under pretty elaborate rules (including penalties for not showing up). 

This is not exactly what you asked (random, instantaneous pairing), but probably the better way. The problem with long time controls online is not only finding people who want to play, but discouraging people from losing interest and quitting.

As far as I know, these were founded on ICC when chess.com didn't exist yet. So maybe there is something similar on ICC.