IPhone 3 running very slow why?

I have a iPhone 3, it's 2 1/2 years old. I'm saving money to buy a iPhone 4S. It's $100 plus $40 activation fee. I hope to have it in a few months.
Anyway, my phone is so slow, closes apps, takes forever to open FB app, and safari pages. Games constantly crash, camera crashes. Is it just getting old? It got worse after I put the 6.1 update on it.Am I just going to have to deal with it till I get a new phone?

Yup you should get the galaxy s3 its AMAZING I don't know how I could have ever loved my 4s cause the s3 is super cool

I have a 3GS and it runs fine on 6.1. Apart from a battery issue (which I think may be related to a faulty battery, and not iOS 6.1) it runs fine. Maybe your phone has too much open, or is nearly full? These are worth a try.

To close things you have open, double tap your home button, and hold the applications that appear in the bottom for 2-3 seconds, then press the red "-" in the top left corner of the app, and it will close it. This will not delete the apps.

To check if your memory is nearly full, either plug it into your computer, open iTunes and click on the panel that says "iPhone" or whatever your iPhone is called and at the bottom it has a graph type thing with your memory. Or to do it using the phone go to Settings > General > Usage and look at the bit that says Used: … GB / MB. If your nearly full, go to the home screen and hold applications for 2-3 seconds, then press the red X at the top of any apps you don't use. This will free up space.

If none of the above work, maybe restore your iPhone in iTunes (this will erase All your data) and see if it helps. Otherwise, I'm not sure I'm afraid…
Hope I helped
Joe