i've just published my first android app in the market: HiddenMenus.
well, it is actually one of the simplest application ever, it lists some hidden tasks/activities like "checkin" (*#*#2432546#*#*) and "info" (*#*#4636#*#*), extremely useful for gingerbread upcoming ota!
since i am a nexus one owner, i just know its codes. feel free to suggest other devices shortcuts.
for any bugs or "force close" it is better a useful reply here rather than a negative comment on the market.
[update] WARNING: some entry might not work depending on the device/rom
thanks to all.