Yeap. currently running LXLE, the LTS alternative for Lubuntu. since it is LTS, i don't have to do much maintenance and just let it auto update itself.
LXLE
http://distrowatch.com/lxleVector Linux is quite fast too.
currently using the LXLE as the main os on the Pentium 3 with 512mb.
another distro that I found, which is really2 fast is Porteus.
http://distrowatch.com/porteus the system is loaded into RAM a-la puppy linux and the design is very modular such that apps are packaged into modules and you can swap the modules as you wish before you load. most of the apps are also compatible with various DEs. it currently supports kde4, lxde, xfce, mate, razor qt.
running porteus from a USB on a slightly newer PC with 2GB RAM and it flies. enabling zram helps too. currently has it setup to run if the family just need to browse web, they prefer the KDE interface too. try it out here
http://build.porteus.org main site here
http://www.porteus.org/ 
it has replaced my go to bootable usb from puppy linux to porteus.
there are other distros that can run from RAM, and they are generally faster if you have an older PC, with decent RAM size.
list available here
http://en.wikipedia.org/wiki/List_of_Linux...at_run_from_RAMranging from very minimal ram requirement of 4mb to 4gb.
This post has been edited by azrash: Dec 19 2013, 12:44 AM