What do they all have in common?
Each and every item has his business name on it and they are all useful items that I WILL use (and am using!).
A great way to remind customers about you is to send them something they can keep and use. I like to send pens (I'm a total pen hog) for Casto Creations that have my business name on them. They're useful and remind people that I'm around if they need me.
Promotional items do not have to cost a lot - even when personalized. From pens to candy and even more off the wall things like promotional Gumball Machines, anything you can think of - Site Impressions can customize!
People love free goodies, so if you do spend money on personalized items be picky about when to hand them out. If you get something a little higher end hold a contest for it instead of just handing it out - and collect e-mails at the same time.
I'm a huge fan of promo items - luckily Aflac has a TON ... so I have to watch my own budget so I don't go overboard. :)