I love web apps that are very easy to install and use - and have an ongoing benefit. Priceheat falls into this category, because it literally took me 10 seconds to install and I can see myself using it a lot. To install all I needed to do was drag a link from their website onto my Firefox toolbar. Priceheat is described as a "a one-click Amazon price checker, a bookmarklet, a widget, price comparison 2.0." Despite the inevitable "2.0" moniker, what it actually does is provide a one-click way to find the cheapest price for an item. For example, it looks like I'll be buying the new Pearl Jam album from Amazon (I don't know what J & R is):

I asked Veronika from Priceheat what their business model is and that too is refreshingly direct:

1 - Make fast, simple, easy to learn tools.
2 - Get them out to users as beta, get real feedback, and tweak.
3 - Sell the product when mature to a partner with marketing muscle.

This is what I hope personalized computer agents will be like in the future - simple to install and run, plus very useful!