Spiky Latency

[Bonsaii]

Hey all, I've been trying to help out a friend of mine with his lag issues. He's a guildy and an incredibly good player thats really limited by his lag.
While on the internet (WoW or otherwise) he experiences huge latency spikes. This has recently become a big issue for him since he wants to pursue raiding to a more competitive degree. I had him use speedtest.net and he came out with a decent score (sorry don't remember for sure, something like 80 Mbps down, 16 Mbps up, and a 26ms) with a large discrepancy between his upload and his download.

I'm wondering what could cause this and how to fix it (other than changing ISP) and whether or not there may be a program out there for evening out his latency, he can handle lag, just not spikes.

EDIT: Preferably something like this, I use it on my own machine but he says he has an MSI board.
http://www.asrock.com/feature/xfastlan/index.asp