http://www.hobbymagic.com/dvd-r.htm its the top disc, the 3inch big ones, 1.5gb storage capacity, same size as gamecube discs, it sias there compatible on it too, i dont know if anyones tried them yet

Yes, it's compatible with most media.

Yes the mini DVD-R should fit in the inner tray of your 105 and have no trouble reading. Although I thought that there still wasn't a complete solution for backing up game cube discs (my understanding is that gamecubes are read backwards). I have yet to see a modchip that will allow your GC to read backup games either. The only mod that I know exists is the one that allows the GC to be region free and play imports. Anyway at $8 a pop you might want to look into the afore mentioned statements. I would also be curious to know exactly what color the dye is on the back of them (dark purple dye on Ritek dye discs well known to be the best). It would be terrible if you spent all that money on these discs and they don't read because they are poor quality media (although at $8 a disc they shouldn't be).

I know gamecube games aint been ripped yet, but once they find away to backup the contents of cube disc onto pc, then burn it on the dvdr it should be solved, i didnt gamecube checked for copy games anyway, as nintendo were sre no one cracked it, anyhow im sure the panasonic gamecube would soon sort this out

This is true but man Panasonic gamecubes are SPENDY!!!! Anyway you might want to wait on these discs until they get close to actually getting the GC backups up and running to give the media a chance to go down in price a bit.