Oh Lordy, Richard. You are definitely up for a new one. My advice is don't think of it as just a phone. It's a minicomputer! I use it about 5 times a day as a phone but more for the 3G/2G updates on news, email, imessage, camera(it takes beautiful photos and video), books, and my favourite music. While at work or in the car, I listen to my music. It's my mini iPad as my iPad 3 is wifi so when I can't access wifi, my iPhone 4 takes over. Loads of contracts out there from £29 upwards (down payment) and 18/24 month contract. You won't regret it.
Don't forget I still love my iPhone 4 so you aren't necessarily going to have to buy the 5. There are 3 beautiful versions of these wonderful idevices. I'm on Tesco O2. I've never regretted my decision, ever! I wouldn't go back to my Samsung phone.
I'm not sure whether Tim has upgraded his iPad 1 yet. I'll ask.
Sent from my new iPad using iPF