MongoDB.com is another cool project I am following with great interest...

One of these days... one of the big boys is going to start hosting a large database like this... and you will be able to migrate into and out of it on a whim...

think google app engine but with out all the hassles of porting your data... ( just add them to YOUR cluster and pay for what you use )

that would come in VERY handy for my current port of web form to email...