While the switchable graphics tutorial from a couple of days ago will get you up and running nicely on the integrated graphics, it will not get you anywhere with the hardware acceleration on your discrete card. At least not on the Envy 14 or any other machine that uses the 'Evergreen' series of ATI cards while running Ubuntu 10.10. The issue is that the newer open source driver that has the code to use the discrete graphics cards hardware acceleration isn't supported under the 2.6.35 kernel. Its possible to get the graphics card up and running with hardware acceleration under 2.6.37, but sadly doing so at this point will break the touchpad patch from earlier. I'm currently in work on a fix for this and will be quick to submit the change to the patch and also to put up a tutorial as soon as I can.
It should be noted that updating the kernel to one of the mainline kernels will make it very difficult for you to get support on the Ubuntu forums as you are moving away the standard system. Also while it may fix the graphics, its not uncommon to deal with feature regression even though you are updating the kernel. Its not hard or even impossible to boot off an earlier kernel that is still install on your system. In fact, this is why you are by default given the boot choices in Grub upon boot. Just in case a new version of the kernel breaks your system you are still able to back track.
Tutorial to come soon!
Also feel free to drop off a comment or an email if you have a particular feature or issue you'd like help setting up.