Iphone 4s randomly running slow?

My iphone has been randomly running extremely slow for like the past two months. It will be normal most of the time, then it runs supers slow randomly for like a week, then goes back to normal. This is ecpecially noticeable on videos and downloads. Any ideas to what's wrong or how i could fix it!

How to uninstall jailbreak off a iphone 4s?

I have already done the process of plugging my 4s to the computer, backing up my apps/photos (which, takes a while) and then pressing "restore" takes me about two hours just to get told there's an error. I have tried this process twice with the same result. Someone please help me. Jailbreaking was a terrible idea and I really want to get rid of it.

How to get the iPhone 5 without paying full price?

I found out that if I turn in my iphone 4 then I have to pay $645 for the 5. Might as well buy the unlock one but I don't want to pay that much. I should just deactivate this one so I can spend $200 for the 5. Any other ideas?

How much can I get for a used Nintendo DS Lite?

I'm 13 years old and saving up for an iPhone. I never use my DS anymore, so I decided I wanted to sell it. I already know what website I'm selling it thru, just not the right cost to put it up for!

Info
-Used Black DS Lite in mint condition
-No scratches
-Comes with 2 stylus and a carrier bag with a retail price of $20
-Selling 5-10 games with it

I went to Game Stop and they would give me $40 in cash for just the DS alone, but $60 in instore credit. I need money though, so how much do you think this would go for?

Trying to sync iPhone to Macbook as usual, but Macbook now too old?

I'm trying to sync my iPhone to my Macbook which I've been doing for a year successfully. Now it seems my computer is too old and my phone far too updated.

Error message:
"The iPhone 'My iPhone' can't be used because it requires iTunes version 10.6.3 or later. Go to www.itunes.com to download the latest version of iTunes."

I tried re-downloading iTunes to my computer but the new iTunes 10.7 version is too new for my computer, Mac OS X 10.5.8. What can I do to have a successful sync besides get a new computer?

Added (1). I updated software on the "Software Update" and it is still a Mac OS X 10.5.8 -- Thanks for the response Duncan!

Added (2).… Right but i still need help with my question!