While a fairly low-level spell, I don't see this one getting a lot of table time. Largely, I think, because it has a pretty narrow focus and the cleric would probably want to know in advance that it would be useful before preparing it.
Snake Charm (2nd level Clerical Spell, from Cook)
The cleric can charm 1HD worth of snakes per level. Given that the biggest "normal" snake in the books has 5HD (Rock Python), and the cleric needs to be at least 3rd to cast the spell, chances are he can deal with at least one reptile. The description doesn't specify whether the snakes get a saving throw vs the spell, but my assumption is that they would.
What's interesting is the nature of the "charm." The snakes won't do the cleric's bidding, they just rise up and sway, like in the movies.
Hostile (attacking) snakes will only sway for 1d4+1 rounds. Neutral ones will be "charmed" for up to 5 turns. Plenty of time to get past a nasty save or die situation.