I have seen varying opinions across a handful of stackexchange sites as to how long you should wait to accept an answer. This answer claims that you should wait as long as it takes to get a correct answer, but you may accept immediately after you get it.
I kind of see the accept check as a low-grade bounty, and typically once it has been given, people are less likely to answer (I don't have any proof for that, but it is probably true). Bounties require 24 hrs to award for many of the same reasons why you might want to wait to accept an answer. So why isn't accepting held to the same time restriction as awarding a bounty?