I'd say that a netbook with 3g internet would be a worthwhile investment, so you could check for new deals even while your out on the job. Then you'd always have your next destination, you could plan routes efficiently, etc.
It's pretty cool, wish I've known this app when I was looking for a free carpet.
Interestingly enough, just last month, I bought on CL and sold a pair of girl's snowboard boots for $15 more in a matter of 4 days. Mostly because I really didn't want it.I was just practicing on my selling skills. I'm more inspired after reading this.