From what I can find, it seems like support currently exists in the gesture-recognition framework, but there is a kernel bug that is blocking it from working with Synaptics devices. I found a bug report for it that has a status of "Fix Committed." It seems to indicate that it supports devices that are not explicitly multi-touch.
However, this bug report for an issue with the kernel has been triaged. There is discussion up to today, and it seems like fixes have been committed to the natty git kernel repo that may provide the support you require.
You could try compiling the kernel from this (presumably very unstable) natty kernel snapshot: git://kernel.ubuntu.com/cndougla/ubuntu-natty.git
Or just watch the kernel bug report over the next few weeks and try to upgrade to that kernel version ASAP.
Also, for what it's worth, the kernel issue prevents the framework from working with a Synaptics touchpad, but you might be able to enable multitouch gestures using X11 by following this guide.
synaptics
tag instead ofsynaptic
to put your question in the list of Synaptics (touchpad) questions, rather than with the Synaptic Package Manager questions. (Oh how I long to have 200 rep so I can just do this housekeeping myself.)