How to transfer music from ipod to computer?

I had an itunes on my main desktop computer which i used to get music for my ipod touch. However my desktop crashed and is beyond repair. All the music however is still on my ipod and i would like to transfer it to my laptop, as it seems a waste to lose all of the money i payed for music. i have not been able to update my ipod with new music as this would delete all of the old stuff (around 750 songs). Pease help, all advice appreciated.