Browsers leaking memory (mac mini)

We have a Mac Mini server that is about 18 months old. For the last 6 months or so, the browsers are leaking memory (chrome, firefox, safari) It seems to be worse with flash, but happens with non flash too.
Any suggestions?

Get a cloth and wipe it up.

Serious, just quit the App every now and again. With OS X all memory is recovered after quitting the App.

Were you trying to be rude? Or imply that I am stupid?

I am not a network administrator, technical person etc. I apologize if you think I am inept.

I have shut the application many times, tried different browers, rebooted the machine.
For months, every time I open a browser, very quickly memory starts leaking. If I open activity monitor, it is easy to see the amount of memory being eaten. I can't type letters or do anything after a bunch of memory is lost.

My husband did take the mac mini to the Apple store to see if he could get some help to solve the problem and they told him the stores don't support that product.

I am merely trying to get some ideas about what the problem might be and how to solve it so the computer is usable. It worked fine for some months, but now is a mess. Only thought I have is to reinstall everything, but I'm not a technical person. We need the computer though. I avoid this computer because I have to keep shutting things down, rebooting and the memory quickly leaks yet again.

Its a bit hard to tell...

Perhaps, you could tell us just what version of OS are you using and how much RAM you have, maybe even how much Real and Virtual Mem the App is using.