ALSO: If you go to a public school, if you can sneak onto a computer for 15 minutes and a flash drive, some have super-fast connections to IDOJ
My school's connection to IDOJ is nearly instant-- I can download an episode to the school computers in under five minutes and ep.
Since I'm Assistant to the Yearbook Editor (yay!) this year, I have a password to my school's "secret files" (My teacher always says this... it's just the files that students can't usually access, so that they can't change the settings on their accounts and stuff or change the "safe" sites to look at...
dirty things 
), and I have all the episodes stored on my school account, so I don't have to redownload them. I can take home one or two at a time with my flashdrive for video-making and watching perposes...
If you can, though, I suggest keeping them on at home permanently (instead of at school), or a portable hardrive/flashdrive, or a CD backup... I had to redownload most of my episodes because the school wiped their harddrives over the last year summer.

It was my dumb mistake to make, and I'm still missing a couple eps now, I think... *shrug*
Not sure if this is good information or not, because I don't know what your school's rules are about downloading. Most kids at my school aren't allowed to keep as many files as I am, because I have about 3,000 pictures from this year alone lined up for the yearbook, and I'm also invovled in other clubs and stuff that boost up my account size, because I need to store video from our science olympics competitions and such.