"Position is fixed for the entire hand in Omaha Hi-Lo, just as in Hold'em. This means that if you are in late position and the pot has not been raised, you can see the flop with hands that are a bit weaker than you normally would consider playing, because you have less chance of being raised. Position can give you an opportunity to get lucky with certain hands that can't profitably be played in a raised pot." 1
In a typical ten-handed game, Early Position includes the two players to the left of the blinds (and after the first round of betting also includes the blinds) Middle Position includes the fifth, sixth, and seventh players to act Late Position includes the eighth and ninth players, as well as the 10th who is the last person to act, which is the dealer.
1. Reprinted with permission, from "Poker for Dummies", by Richard D. Harroch and Lou Krieger, IDG Books Worldwide, Inc. ©2000