Reaching Chambana by Air is easy, given that the University of Illinois has its own airport. The Willard Airport (IATA: CMI, ICAO: KCMI, FAA LID: CMI) is located at the Village of Savoy, just a few miles south of Champaign. Just take Route 45 southbound from Champaign (it's the Neil Street inside Champaign, and Dunlap in Savoy).
American Airlines (via American Eagle), Delta, and NorthWest Airlines operate out of here. AA connects to its hubs in Chicago and Dallas Fort Worth. Delta connects to its hub in Atlanta, and NorthWest takes you to its hub in Detroit.
For a limited time, there was a small airlines that connected to Las Vegas, but it moved away in early 2008.
One thing to consider, flights from Chicago O'Hare to Champaign Willard often face bad weather, so be prepared to handle last minute flight cancellations.
Willard Airport has some really nice features. Internet is free for people with a UofI account. Also, check-in times are quite short. Parking at the airport is available at 10 dollars/day.
The other nearby airports include the ones at Decatur, Bloomington-Normal, and Springfield. And of course, you have good ol' O'Hare and Midway at Chicago.