The plugs/sockets are different, so you'll need a travel adapter so you can just plug things in. You can often find these in drugstores - this is what a UK plug looks like: http://www.cellphoneshop.net/ukplug.html?CAWELAID=993626248&gclid=CLC0h9Ci3q8CFQJdhwodYG54Ag
Voltage is 240V AC in the UK (while continental Europe is 220V - they're both close enough to be essentially the same). For most electronic goods that have separate power units (camera charger, cell phone charger, laptop adapter and so on), the adapter or charger will have a note somewhere on it indicating the voltage range it can take; this is nearly always 100...240v or similar for most modern electronics. If that's the case with yours, then you can just plug it into the adapter as in the picture above, and it will work just fine on UK voltage.
If you have some item that is only rated for 110, then you'd need to buy a more expensive voltage converter unit. (It's somewhat rare to actually need this for casual travel, though; most personal electronics work fine on 110 or 240, and the things that are voltage-specific tend to be appliances that one generally doesn't bring on vacation.)
Not sure about the hair dryer, though; most hotels have these anyhow, so you may be better off leaving yours at home. (Not an expert, but I'd be wary of pluging a heating device rated at 110v into a 220v source for fear of it overheating.)