Look at what I found... this true?
Since i was pretty surprised, how a lot of people still doesn't
know this way of increasing your level cap without any restrictions
applied, decided to post it.
This "mod" is very simple:
Use console command "setgs imaxcharacterlevel ##", without "", where ##
you must enter desired cap. No karma reset, or any other nasty things.
Good luck!
Addition: with reload of the game you will got to re enter the command, but the experience, perks, skills are not going to dissappear. Parameter just doesn't save i believe. Atm i don't know a way to create autoexec file in fallout 3.