Can I do anything to make my gas oven better? I have an old gas oven at home which is generally pretty rubbish at most things.  The temperature in the oven is wildly off compared to what the dial says it should be; there are hot/cold spots throughout; the top temperature is adequate for most of my needs, but on occasion I've wanted a really hot oven and it's never been able to get there.

Is there anything I can do to make my oven better? How can I hack it?   I've just bought a probe to use with my digital thermometer and the oven, but I was wondering if anyone could recommend anything else?  I've considered the following options, but unsure if they are good ideas or not:


Putting a fan in the over to help circulate the air around.
Getting a pizza stone to put in the bottom of the over to keep heat when opening the door


** edit **

I would replace the thing but my kitchen is really small so I'm stuck with having to buy a very narrow oven which severely reduces the selection I can choose from.
I would suggest adding some mass to your oven but not in the form of a pizza stone but rather in the form of a 1/4inch thick piece of steel. This not only will hold the heat well but you can make killer pizza that way too. 

Also, does your oven have a broiler? If so I would say see if that can help heat it further. On some models you have independent control of the broiler and can run the oven and the broiler at the same time.