PAYG phone with MP3 player, memory card slot and £5 airtime for £25. This is probably the best-equipped phone I've seen for the price.
Even comes with £5 airtime, so you can use it straight away.
250 phonebook entry capacity
MicroSD (Transflash) memory card
2 embedded games
Up to 7 hours talk time
Up to 250 hours standby time
Includes 5.00 airtime