Quoted By:
If you're going to Lv100, get Meowths. They can learn Pay Day, Thief, and they have Pickup. Payday at Lv100 gets you 1000poke per use, and Thief lets you steal shit from wild pokemon if you don't want to catch 20 of them to find one that's holding the item you want. I've planned this out.
Also, if you just want Pickup, at level 41 exactly (check the bulbapedia) your Pokemon has a 10% chance to pick up a Rare Candy. There is no point training past this, as it will not increase your chances of finding Rare Candies.
Also, you should get an Aipom, because Aipom/Ambipom are the only Pokemon with the ability Pickup that are in the Fast experience group, meaning that it takes 800,000 EXP to get it to Lv100. The next lowest EXP category that any Pokemon with Pickup has is 1,000,000 EXP, a 25% increase. This means that Aipom needs 55,137 EXP points to grow to level 41, and the Pokemon who share the next lowest EXP category need 68,921 EXP to get to Lv41.
Any more questions?