Given that you specifically state "small rare earth magnets" I can tell you the data will most definitely not be affected, but let me lay out my argument.

A magnetic field can induce a current - BUT this requires a pulsating magnetic field. Your rare earth magnets create a static magnetic field, so technically only if something moves in the magnetic field could a current be induced, but this would be very weak.

Secondly, while I believe the mirror is magnet driven, there is no other "magnet based technology" in use around a DSLR. CF or SD cards do not use magnetism to store data - harddrives and tapes did. Hence CF and SD cards are immune to magnetic fields (as long as these do not induce currents in the cards.)

Finally, magnetic fields do no penetrate very far. Magnets or electromagnetic field strength decreases proportional to the square of the distance. -> I.e. what is technically already a weak field (rare earth magnets are in practice not that strong relative to magnetic fields induced by coils for example where required) and they won't go very far.

Finally, many items nowadays use magnets for closing mechanisms - BlackBerry holsters have done so for ages, the PlayBook sleeve does too as does my Sony eReader cover. Heck, some laptops even have a magnetic closing mechanism and thus get rid of the button one used to have to slide.

On this basis I'd say it is pretty safe to use magnets around electric equipment without any issues. (Note: Don't do so next to an old cathode ray television, if you do you'll have to recalibrate the thing... but do these still exist? :))