Thanks! I guess it did come via the compost. I'll think I'll keep it :)

I'm pretty sure it's in the saxifrage family...and I have a hard enough time with a few of them when they're in my hand! So here's a site to help you key it out...now you just need a magnifying glass! Oh, and a computer on hand to look up the botanical terms! Here is a link that might be useful: Saxifrage family

Let me try that link again.... What true Geraniums are tri-colored? Do I have a new mutation here? The other thought is that its a weed and a variegated mutation. (The geranium probably just hasn't emerged yet.) I was leaning in that direction but I posted in the weed forum and both respondants thought it looks like a geranium. Here is a link that might be useful: unsolved Name that Plant post

Let it dry out totally between waterings. Sounds like you are drowning it. But to be safe, take cuttings.