Can't turn on Mini, or reinstall OS X

Hi guys-
First off, I apologize if this should've been in the software forum as opposed to this one.
My problem is this: I finally updated the software on my Mac Mini (which is running tiger). It was almost done installing the software update when it said that it couldn't be finished. After that, my computer froze. When I tried to restart it, it would start to turn on, then say there was an error, and I needed to restart. Even if I restarted, the same error would happen. So I got out my OS X install discs to reinstall the software. Unfortunately, it cannot reinstall OS X, because I don't have enough free disc space. It claims my only option is to erase my hardrive, which having all my music and pictures, is not something I'm rushing out to do. Luckily, this happened just after finishing my college applications.
Does anyone have any ideas or suggestions as to how to get my computer to turn on? Kind of ironic that my nice Mini isn't working, so I'm using my mom's Pismo lol.
Thanks and peace,
-Brady

No one has any words of wisdom? Thanks.

You can use target mode and retrieve your music and pictures from the mini's hard drive. Connecting you mini to the pismo using a firewire cable. Then you can do the fresh install as the system suggested.

To boot from target disk mode, you have to hold T while booting. Then just connect it to another computer (if PC, then you will need macdrive) and retrive your data.

I'm not sure if this is possible, but you should be able to connect a USB drive to the machine while you boot from the install DVDs. Just make an image of your "Mac disk" onto the "USB disk" (that is, the USB disk has to more than the size of the Mac drive.