Puppy Linux is not only lean, it's also lightning fast. On boot, the entire system loads into RAM and runs from there. If you are using Puppy Linux on a notebook or netbook, this also helps to increase battery life since the machine doesn't have to access neither the hard disk nor the CD/DVD drive.

Puppy Linux is probably the most versatile Linux distro out there. You can run it as a Live CD, install it onto a USB stick or a memory card, and do a full-blown hard disk installation. Even if you run Puppy Linux from a rewritable CD or DVD, you can still save your settings and data (provided you have a CD or DVD burner).

If you install Puppy Linux on a USB stick or an SD card, the system automatically saves all your settings and data in a single .2fs file, which makes it dead-easy to back up your data and upgrade your system. Moreover, Puppy Linux features its own .pet package format and a package manager which lets you install additional applications with a couple of mouse clicks. Better yet, Puppy Linux supports .sfs packages, so you can install applications by simply copying the .sfs file to the /mnt directory and pointing Puppy Linux to it (see, for example, the OpenOffice.org on Puppy Linux post).

Puppy Linux comes with a raft of lightweight applications and tools for every need. Word processor, personal finance manager, expense tracker, graphics editor, audio and video players, and even a blog engine -- Puppy Linux has it all. It also supports the mp3 format right out of the box.

But the obvious reason for giving Puppy a try is that there is no reason why you shouldn't. Puppy Linux doesn't cost a dime and it's only 96MB in size, so you can download it in a matter of minutes.