Temp Probe

Sure, everybody uses them. Search the forum for "Polder" or "remote probe". A fairly cheap, quick option is to buy a Taylor brand at Target for around $18. Poke the L-shaped probe down the top vent - looks like it won't fit but it will if you shake it a bit - and put it in your meat.

Here's a pic showing how to use a remote probe.

http://www.lamaine.com/bbq/images/images/readytogo2.jpg

Good advice above, but stay away from the Polder dual temp unit. It looks like a neat unit but you will be lucky if it lasts two weeks. The Taylor that tjr mentions & that Dave's photo shows is the way to go...the model that I use is actually called a TruTemp (by Taylor)from Target. I modified mine before the first use by using a 2 inch section of heat shrink tubing over the wire connection where the wire enters the probe to prevent any chance of moisture entering the probe.
CB

I have used my polder for 9 months now with no problems but it does seem a lot of people have problems with them and use the taylor instead.

I have had my Nu Temp for four years without any problems. It will monitor three seperate items at once.
http://www.nu-temp.com/bbq.htm
Fast Freddie

get a taylor from amazon/ jan

You can get the Taylors at Target for about $17.00. They work fine and already have a piece of plastic shielding where the wire enters the probe.