Ubuntu is a community developed, linux-based operating system that is perfect for laptops, desktops and servers. It contains all the applications you need - a web browser, presentation, document and spreadsheet software, instant messaging and much more.

Welcome to Hardy Heron Alpha 5, which will in time become Ubuntu 8.04." Features include: "X.Org 7.3; Linux kernel 2.6.24 with dynticks support for amd64; PulseAudio enabled by default; PolicyKit integration; Firefox 3 Beta 3 with much better system integration; GTK+ version of the popular Transmission BitTorrent client; new Vinagre VNC client; Brasero CD/DVD burning application; World Clock Applet; GVFS, the virtual filesystem abstraction layer that's set to replace the ageing GnomeVFS; ufw (Uncomplicated Firewall)

This VMWare image lets you try it out without installing it or even rebooting your machine, and works in the Free VMWare player.
Login: vmplanet
Pass: vmplanet.net
md5sum: 990e2e9175d87810543bf240f88cabe2 Ubuntu8.04a5.7z

Ubuntu 8.04 Alpha 5 VMware Image (load balanced mirrors)