For some reason my iphone has started to run very slow.

What can i do to make it run like it did up till a couple of days ago?

it has all the up to date stuff and i dont run that many Apps but its doing it when i use the internet as well.

Any ideas guys?

What changed?Any updates, new apps? What did you do? I guess you already turned it off and on and it did not help.

Try holding the power and home button together until it restarts, failing that do a restore

Yep turned it off then on again and still feels the same,

I have only updated the Seesmic app that i have but it was running slow before that.

if i do a restore will i lose everything?

Not if you attach it regularly to iTunes. Only thing I had to re add was my music as I do that manually anyway.

Also, try removing the sim and reinserting, that sometimes cures things.