If you want potential customers to remember your business long after the trade show is over, be sure they leave your kiosk or booth with something that has your name on it!
Don’t waste your money and their time on something that has no real use; people have more than enough pencils, combs, and keychains. If you’re going to invest in a branded “souvenir” that you hope people will look at and be reminded of how good your business potentially seems to be, send your booth’s passers-by home with something substantial, small (if it’s too big to fit easily on a plane, chances are good that the customer won’t bother to take it home.) and USEFUL!
Flash drives are my personal favorite when it comes to a branded freebie.

Businesses display their goods and services at trade shows in order to demonstrate to potential customers what that business might do for them. To do this effectively, the trade show display must have instant customer appeal. In addition, once the potential customer’s attention has been captured, the display must be such that the customer can truly appreciate the goods/services being marketed, and can retain and recall this information at a later date.