I don't know anything about Chicago, but a tip from just having been to the Portland Expo... take along a ton of address labels. There are so many companies that want your info before they'll give you that stupid free pen, that it makes it easier just to peel and stick a label and not get hand cramps.
Also, go early and get into the Safeway booth first (or whatever major grocery chain in your area is set in the center of the Expo center)...they are giving away OneTouch US, Freestyle Flashes, and Accu-chek Avivas. They are also giving away "sick day boxes" and various other goodies, along with a coupon to get a $20 gift card with a new or transferred prescription.

I usually only get my insulin and test strips from Safeway, but next time I need something, I'll get it there with that coupon. (And I know you're like me and do the coupon thing.

)
Lots of companies are doing free screenings there, so you can get your A1c, blood pressure, etc. checked too. The best freebie was a drawing done by the Exubra (sp?) people, who do 3 drawings for iPod Shuffles. You must be present to win. They are also giving away pedometers that are pretty cool, and digital.
Didn't mean to hijack your thread, Kev...I should have probably written up a review and put it somewhere else... My real point was to really just tell you about the labels! LOL