I dont think iPod allows you to do that. You can transfer songs onto the iPod, but not from the iPod. It's like part of an anti-piracy thingy. If you put all those songs from iTunes onto a CD, then take it to your friends PC, you can upload it to his/her iTunes, and from there onto the iPod. Or the easier way would be to tell your friend to take his/her iPod to your PC, and upload them from your iTunes (assuming you still have them on there).
From iTunes, you can't transfer songs from your iPod.
You can, however, just put the songs onto your iPod like you would a USB stick (My Computer -> iPod drive) and just copy and paste all your music there and then transfer it onto your friends computer that way.
Well if you have a Mac or a Macbook you can simply Download a Program know as IRip. What it does is Takes songs off of your Ipod and puts them into your Itunes Library. This way differant people can steal your stuff if you have music from mutiple Librarys. Remeber its for Macs only. But i can probally guess that you dont have one. Just use this if in the future you do.