Linux-based Internet Tablet Nokia N800 is very popular. Even coming N810 is not going to replace it completely (I’m not talking about windows-based Origami). Using Maemo SDK it’s fairly simple develop new applications or porting existing ones. For sure to be success you need a right documentation. Following article from IBM.com explains obviously how to use N800 camera API.
P. S. The easiest way IMHO to setup Maemo development environment is downloading the Maemo SDK VMware Appliance. It can be run with free VMwave Player which available for both: Linux and Windows.