I'd like to try the new version but don't want to replace the old version. Are there any binaries I could use?
It is possible to install LibreOffice in a directory, and run it from there.
For more, see
You could load up a virtual machine, install Ubuntu in it and consequently install the 3.4.0-beta5 .deb package in the Ubuntu install in the VM.
This method obviously won't replace the old version, but strictly speaking you are still installing LO 3.4.
Thats indeed the best method as some important things (like desktop integration) cant be tested with parallel installations, but can in a virtual machine. Also: LibreOffice 3.5.0beta2 is available in Ubuntu precise: launchpad.net/ubuntu/+source/libreoffice/1:3.5.0~beta2-2ubuntu3 Jan 19, 2012 at 9:21