A more local place to go that is still close to the hotel would be Moretti's in a little neighborhood called Edison Park.
http://www.morettischicago.com/ep/index.php
It's a nice local place that has an huge outdoor seating area. But again the problem would be showing up with 20+ people and expecting to get a table on a Friday night. Edison Park is only 2.5 miles from the hotel.
http://maps.google.com/maps?f=d&hl=...sspn=51.621706,92.8125&ie=UTF8&cd=1&z=15&om=1
I can imagine a cab ride would cost all that much if we got minivans and packed in 6 or 7 people per van. It all depends on what people want to do.
Edison Park also has other bars / restaurants all within a few blocks of each other. This is the area I normally go out in. Like Kristie said it's a 45 minute 1 way ride downtown on the blue line.
Another option might be a place called the RAM which is close.
http://www.theram.com/il-rosemont.php
It is about 1.5 miles right down the street. Cabs would be cheap going there. They have good beer....but again it's a chain...they are open until 2AM on Friday nights if I remember correctly. I am thinking they may be able to accomodate 20 people on Friday night easier than Hooters or Moretti's in Edison Park. The place is much bigger than Hooter's inside. The RAM is one of our drinking establishments after work since my office is right across the street. So I know they have decent food and beer.
Anyplace is fine with me. I'm there to meet the JC crew and have fun. I can do that at any restaurant / bar we end up at. I'm just throwing out suggestions since I live and work in the area.