The clever guys working on the DSLinux project have spent quite a bit of time with Nintendo's premier handheld device, reason being:

"You can use DSLinux as a filemanager, edit and save text files with vi, play simple text-based games, and play mp3 files."

Most recently, PepsiMan (one of the project members) revealed on his blog that rudimentary Wi-Fi support has been added to DSLinux, thus opening the door for wireless networking and web browsing sometime in the future.