The Nokia N900 has a secret FM radio receiver which is not on the official specs. Although it's hidden by default, you can unlock it by installing a special unofficial application, as shown in the video below. The video also briefly demonstrates the N900's FM transmitter which lets you listen to music files and internet stations on any nearby FM radio (which is quite handy in a car).
Click here for a complete list of All About Maemo's Nokia N900 Tutorials
The Nokia N900 has a secret FM radio receiver which is not on the official specs. Although it's hidden by default, you can unlock it by installing a special unofficial application, as shown in the video below. The video also briefly demonstrates the N900's FM transmitter which lets you listen to music files and internet stations on any nearby FM radio (which is quite handy in a car).
(You can also view this video on All About Maemo's YouTube Channel.)
Long-time users of Maemo devices will of course remember Nokia had this same hardware easter egg on the N800, which was unlockable in a similar manner.