Something that relates I guess. The tool acts as your default browser, opens when you click on a link or url shortcut and presents you with a list of configurable browsers.
I do like the icon that a similar app for the mac uses at
Choosy - A smarter default browser for Mac OS X
The icon should match the general style of Windows 7 icons, ie. glossy and not too square, I suppose. Other than that, you're the creative ones