I recently finished reading through Small Stakes Hold'Em (by Miller and Sklansky) and was surprised to read how many more hands were profitable to play. As long as at least four players typically see a flop, you can play something close to 20% of your hands. I thought the recommendations seemed extra loose, but I've been 3-tabling with their starting hand selection for a week now and have had superb results.
I'll give a few examples:
In EP you can limp in with any two suited cards ten or higher.
In MP you add all pocket pairs, AXs (s000ted), K9s-K8 [and a few other hands]
In LP you add suited connectors down to 54s, and any two offsuit cards ten or higher.
From SB you add ANY two suited cards.
All of these assume there typically is four or more people seeing flops. In other words, only in the looser low-stakes games.
The SB recommendation seemed the loosest one to me. But so far it's worked out nicely. You only pay a half-bet when there's already three or more bets in the pot.