i've tried the rubik cube for a while when i was about 12, but i couldn't solve it... i don't know if i could do it now that i'm older, but i guess not and i'm definitely not bored enough to try it.
but at least i did manage to solve the rubik's clock. that was at around the same age and i had figured out my own system for that... i was pretty proud of it at the time, but it's much easier than the cube and i just saw on youtube that there are people who can solve it in around 12 seconds...
you can play some rubik's puzzles online, but it's more difficult than when you actually have them in your hands.
rubik's 3x3 cube
http://rubiks.com/lvl3/index_lvl3.cfm?lan=eng&lvl1=commun&lvl2=cbegam&lvl 3=vrtcub#
rubik's clock
http://rubiks.com/lvl3/index_lvl3.cfm?lan=eng&lvl1=commun&lvl2=cbegam&lvl 3=rubgme&lvl4=rclock