If you're talking about monitoring your case temp, yes there are lots of options. Any of the usual cooling sites, such as www.casecooler.com http://www.svcompucycle.com/ have hardware you can use.
I take a simpler approach. Your local Wal-Mart or Target or hardware store will have a cheap remote thermometer that would be used for monitoring the outdoor temps from indoors. I put the thermal probe inside the case and mount the little readout on the side of the case.