I want to create an image what a web page looks like, e.g. create a small thumbnail of the html + images. it does not have to be perfect (e.g. flash /javascript rendering).
you can get it nearly perfect, and cross platform too, by using a browser plugin.
FireShot or ScreenGrab for Firefox.
6 Google Chrome Screenshot Webpage Capture Extensions
BrowserShots is an open source project that may have some code you can use.
also see: