Where does your sister live? Int he area? Will you be spending the night? What is your "cab" tolerance? And what do you like to do? Art institute? Museum of contemporary art? Milennium Park? Michigan Ave shopping? Outlet mall shopping? Foodie shopping? Jazz clubs? Funky little joints? Shows?
What do you want to do?
There's not a lot nifty near the airport. If I were you I would cab it down town and stay there. Or if the party is all about being together rather that seeing Chicago, head west and stay in a suburban Raddison or something and hit a mall and shop.
Linda C

The Science and Industry musuem is having a free day on Feb 29. General admission is free and you would have to pay for any extras like the Omni Max movie. Parking is $14 but you are allowed to bring your own lunch inside instead of their cafateria.
O'hare is actually closer to Woodfield mall. It is, was, maybe the largest mall in the U.S. After they built Mall of America they lost the little. Then they expanded and got the title back. Now.....i dont know if they still are. It is something to plan if your not up for outdoor shopping.

I am from Chicago and had a reunion to go to 4 years ago They held the reunion in a hotel near the airport. when we hailed a cab, we gave him the address and I asked how much it would be before we loaded our luggage in. The cab driver said $50. We immediately rented a car because it wasn't that far. They may have a set rate to go from airport to downtown.
So either rent a car and stay in the suburbs near the airport or take a cab and go downtown. The fun of Chicago is the museums, the shows and the wonderful parks. The HOliday Inn on the Lakefront downtown is within walking distance to public transportation and Chicago has a wonderful bus and subway elevated system.That Holiday Inn was reasonable, clean, great views,etc. I had a great time taking a bus along the lakeshore to Milennium Park, Art Institute, etc. Easy town to get around in downtown. Its laid out in a semicircle around the lake. I walked to great little restaurants. wonderful Greek food, Italian, etc. Next time I was there, my husband and I stayed on the South Side at the convention center and were able to take the el/subway to downtown, to go to the Irish bars across from the Art Institute.(which has a great collection of Impressionist paintings)
On the plane I suggest you read the book "Devil in the White City" by Eric Larsen, its a scary story about Chicago during the time of the worlds Fair, and talks about some of the architecture and people that buildings and museums were named after.
On the other hand the time we stayed in the suburbs we found a great hungarian restaurant named Paprikash, and got to go shopping at Sears and visit relatives. Dress warmly, bring a scarf, an umbrella and a GPS and a map.

if you go to www.fodors.com and go to the section called "talk", there is the usa forum and you'll get a lot of advice there. Do a search and it will turn up a lot of previous threads. I get all my travel advice there, it's also a great forum.

I live in Chicago ( well, the 'burbs) near the airport. If you can giveme some more information, like how long you will be here and why you are looking for something near the airport, and if you will have a car, I can give you some tips.

If you don't want to go into and stay in the city, you really will need a car to get around