I recently ran way to much voltage through my Arduino and back into my computer via the USB connection. I'm looking for a USB hub with a fuse or some sort of protection to protect my laptop from these types of mistakes. Any suggestions as to products that would serve this function or other precautions I might take?
Both the arduino and a USB port do have some protection against wrong connections and such. The arduino has a diode to prevent wrong polarity to reach your power supply, it also have a resetable fuse (the kinda big, often green SMD part close by your USB connection on your Arduino) that should protect your USB port pretty good from its side of the cable. Your USB port also have some good protections going on as far as i know, so basically it should be hard to break a USB port by accident.
That was the theoretical part, In real life things aren't always what they claim to be, so I use a cheap powered USB hub, that i always use as a first line of defense.
You get used to what not to do fairly quickly :)
Perhaps what you're after is a ruggeduino - http://www.rugged-circuits.com/ruggeduino/
I get the feeling that this sort of thing encourages bad habits, but then it also encourages more exploration.
You need to think carefully about what you're doing, if you put in any second source of power (e.g. USB + power plug, or USB + a signal from another device).