A new version of the METAbolt thin client for Second Life was released September 3, 2011. This version, 0.9.49, provides support for avatar physics and contacts sets as well as several other new features and bug fixes. Owners of the Pandorabot METAbolt Add-On are encouraged to update. If you currently have a previous version of METAbolt installed then all that is necessary to upgrade is to exit METAbolt if it is running then start METAbolt. You will automatically be prompted if you wish to download and install the update.
If you do not have METAbolt currently installed then you can download the current version at http://metabolt.net/downloadbinary.aspx
The new contact sets feature (METAbolt calls it friend groups) is pretty cool. It allows you to specify groups of contacts and is a planned but as yet unreleased feature of Viewer 2 and Phoenix/Firestorm. The avatar physics feature already exists in Viewer 2 and Phoenix. This allows your avatar to "wear" a physics layer that can specify how you want your breasts and rear to bounce.
Inara Pey has a nice review of the new features in METAbolt at http://modemworld.wordpress.com/2011/09/05/metabolt-updates/
The METAbolt Forum announcement for this release describing the features and bugfixes is at http://www.metabolt.net/METAforums/yaf_postst531_METAbolt-V-0-9-49-0-is-on-release---.aspx