Iphone Wi-Fi range is bad all the sudden?

My iphone all of the sudden started getting bad Wi-Fi reception. I used to have 3 Wi-Fi bars in my room and now i don't have any Wi-Fi bars 15 feet away from my router. There's also a kindle, a laptop, and 2 other iphones in my home and they get Wi-Fi fine. Also i use bluetooth in my car, i have to put the phone on the dashboard in order to get my bluetooth to work otherwise if its on my lap the music cuts in and out. Its a iphone 3gs, its half a year old and it has the latest firmware. Any ideas?

Buy a better phone: P