I have an LP120 as well. I got the whole strobist lighting kit from mpex.com (that's where I got the cactus switches) sans flashes, and an LP120 later.
I wish I hadn't gotten the other flashes I have, and gotten three LP120's instead. I have a Nissin di466 and a used Canon 550EX. The Nissin was a mistake. I was looking for a cheap TTL flash, but apparently it can't be triggered by remotes due to having no jacks and not using the standard bottom contact. The 550EX takes FOREVER to recycle, even on 1/2 and 1/4 power.
The LP120 is dead simple. Everything is manual, the zoom is done by pulling out the head, the power is set by switch position on the back. It has a stereo jack, a pc jack, and it can be set off with a hot shoe adapter or optically. I have never had any trouble setting it off with the cactuses. I've had plenty with the Nissin (optically, since the cactuses don't work with it).
If I could go back and do it again, I might still get ONE TTL flash for any on camera use, but I would definitely get two LP120's.
Mel