Hmm, I looked at the index and didn't see anything for Lapras, so I might as well give it a shot.
It's a set that's best used only in rain. Dances circles around anything and everything that likes to run stall with status.
Lapras & Leftovers.
Jolly / Hydration
252 Att, 252 Spd, 4 HP
Waterfall
Ice Shard
Rest
Dragon Dance
This set is simple. Get rain set up with another Pokemon, and when they're either down or you think it's time to switch, bring in this thing. One D-Dance lets you outspeed plenty of things, so you can either Rest off the damage or start hammering away at the opposition.
Even though this thing can survive a harsh blow, it's never safe to bring it up against something that will deliver its own share of pain, unless you're confident of taking them out before you take them out.
A team based on this Lapras set netted me a peak of 1386 points on PO, before BW2 came out. I'm not certain if it's effective in the new metagame, but even so, it's great for anti-stall if rain is the dominant weather there.