Running out of Disk Space

Hi,

I have a Mac Book Pro with a 500 GB HDD.

I curently have just abiut 10 GB of data left. It's now DANGEROUSLY low and I don't know what to do to increase/recover/plan for additional disk space.

iPhoto's takes up a good 250+ GB of space itself.

Any suggestions on how I can keep my MacBook going and retain my data without any loss (and also of speed and reliabliity)?

Thanks in advance for you suggestions.

Regards