Omaha has a few gamers (myself being one), as does Lincoln. But it seems many pick-up games at any store seems fairly scarce for GW games. Seems CCG's have returned to all the rage as has other model manufacturers.
If you have access to phone-books for either town, look up Dragon's Lair (Omaha/Millard), Ground Zero (Bellevue), the Game Shoppe (Bellevue... www.thegameshoppe.com 
or... I'm not sure if Krypton comics does any tabletop gaming.
I know there's a shop in Lincoln, but can't recall the name off hand. I want to say Gauntlet Games, but that might not be right. Hobbytown USA in Lincoln has games from time to time.
I'd be willing to game with you myself, but I'm a lazy arse who can't be bothered to drive more than an hour outside of town for a game with too many models I haven't finished yet.