You may remember back in February the BETA of BackTrack 4 was released for download, the team have made many changes and have now released BackTrack 4 Pre Release.

For those that don’t know BackTrack is the top rated linux live distribution focused on penetration testing. With no installation whatsoever, the analysis platform is started directly from the CD-Rom and is fully accessible within minutes.
It’s evolved from the merge of the two wide spread distributions – Whax and Auditor Security Collection. By joining forces and replacing these distributions, BackTrack has gained massive popularity and was voted in 2006 as the #1 Security Live Distribution by insecure.org. Security professionals as well as new-comers are using BackTrack as their favorite toolset all over the globe.

The new version has busted the 700mb file size though so it’d DVD or USB, it’s recommended to use a USB drive to run it or install it on your HDD as running from a CD isn’t exactly speedy.
Full details available in the PDF guide:
BackTrack 4 Guide [PDF]
You can download BackTrack 4 Pre Release ISO here:
bt4-pre-final.iso
Or read more here.