Linux on laptops

As a preliminary to installing Linux on at least one of my computers, I've been testing live CDs, with varying degrees of lack of success. Both of my working computers (as distinguished from the various non-functioning machines lurking around here) are Dell laptops. The "new" laptop is an Inspiron 1150; the "old" laptop is an Inspiron 2500. On the new laptop, the Ubuntu live CD worked fine, with one exception: it refused to recognise the display screen and so ended up displaying at 600x480, not a resolution that lends itself to getting any work done. Next I tried a Linspire Five-O beta IV live CD. This recognised the screen and displayed beautifully, but refused to work with my ethernet connection, thus preventing me from communicating with the internet. (I was trying out the CD at the Desktop Summit, so a Linspire tech was on hand to spend some time trying to diagnose and fix the problem. Possibly a fix went into the next iteration of Linspire Five-O, but I haven't been able to test it.) On the old laptop, the Ubuntu live CD refused to load at all, freezing completely only a seconds after starting to load. The Linspire live CD loaded, generating some error messages along the way, then at the point of setting up the time, date, and location, it appeared to go into an infinite loop, thrashing the hard drive for over an hour until I got tired of waiting and turned off the machine. Some research on the Web reveals several people claiming to have successfully installed a Debian distro on the 2550, but I'm not ready to tackle a full install yet. Next I'll try a Knoppix Live CD and see how that goes. I've downloaded the ISO but haven't burned it on a CD yet... stay turned for further developments.