It was a while ago that news came out that Nokia S60 devices had been hacked/jailbroken. At that point in time the procedure was complicated and not everybody would attempt doing it. Then Nokia released firmwares that took away this possibility.
But another version of the hack was created, which made it much easier to jailbreak and install unsigned applications and add patches. Jailbreaking/Hacking now takes less than two minutes and you do not even need a computer. I have been mulling over the idea of putting up a guide to doing this, but Mark at The Nokia Blog has beat me to it. Jump over for the complete lowdown on – How To Hack Your S60.
Warning: Once you do this, please be extra careful in selecting the applications you install on your phone.