I made a nice skeleton EXP farm. Basically, you follow the instructions and enchant your bow and stuff. A trapdoor is added in the enchanting room so that you can go into the wild, mine, come back and then chant your picks, swords, armor and other things. I followed a schematic on this website: http://vavo.dk/minecraft/xp/xpimg.htm
The skeletons spawn from the spawner, go up a watervator, then they flow to a 23-block drop that leaves them with 1/2 a heart left. You then shoot them with your bow and their items drop into the water along with the EXP. That water flows to you :D

Additional Notes

None :O