Where to surrender
Actually, surrender hasn't been very common in online casinos, but that recently changed. Playtech introduced a new game they're calling 'Blackjack Surrender', which is six-deck blackjack plus a late surrender option.
I was just planning to do a blog entry about this game, because if you play at Playtech casinos, there's no reason to play their regular blackjack anymore. In order to offer late surrender, the dealer checks their hole card under tens and aces before you're allowed to act on your hand, including surrender. So, that means you can safely double and split when appropriate against a dealer ten and ace, unlike in their regular game.
The Blackjack Surrender game uses US hole card rules, while their normal blackjack game is European No Hole Card rules.
Note that it appears that some Playtech casinos don't have this game yet.
For a list of Playtech casinos, here's a link to my other site:
http://www.slotcharts.com/casinos.php
For another place that offers surrender, try (Dead link: http://bh3.net/l.php/715) _Global Player_.