There's a five-round event at the North Shore Chess Center, 5500 W. Touhy, Skokie, this weekend (Friday night, Saturday & Sunday afternoons).
No prizes to speak of, but this looks like a very cool event--the time control is particularly friendly to serious amateurs. But note the qualifications before you show up! You must have either an established FIDE rating (you can check here if you're not sure) or a USCF rating above 1599.
Details on the Illinois Chess Association website!