Is the Eevee/whatever it is male or female? If male, obviously forget it (besides, I don't want every single one of my Eevees knowing Wish), but if female and you have a male Pansear or Munna that knows Yawn, that would be a nice idea for an Eevee.
Of course, I could always breed one of those myself. But I'm offering you Egg Moves on Weedle. You can't catch it in B/W, you have to breed it; thus, Egg moves are fully possible.
Yeah, I'd rather not take them time to do that. I can still offer you the Eevee though. Or a Rydon, Azurill or Mareep. It's not like Weedle is super rare or anything.
What can you offer for a Weedle? I might start concentrating on completing one Pokédex area at a time, and Kanto seems like a good place to start. I'm most interested in things not found in B/W but will accept White Forest exclusives as I still need plenty of them too.