A lot of people would be dumb to pitch to Google in the idea phase. If you're a first time founder without a convincing, working (and probably already with users) prototype or some really, really convincing connections your email is going to go straight into the circular file.

The "steal my idea" thing is one of those notions that makes sense until you're out there for a little while. I worried about it too until I realized, wait, nobody cares. A lot of good ideas seem to only look good in retrospect.

Google, "We're building better search." "Uh, huh. Yeah. You do that. Graphs you say? Dweebs."

Microsoft, "We're building a commodity operating system." "Without a computer? Why?"

Facebook, "We're starting a social network for college students." "Uhm, like MySpace?"