There are a few types of GEDCOMs that Geni can generate - Ancestors, Descendants, Blood Relatives, and "Forest" which gets you up to 100,000 profiles including all the inlaw trees...
Once you decide what kind of GEDCOM you want - navigate to the profile of the person you are doing the GEDCOM for - and over in the ACTIONS drop down menu - choose the "Export GEDCOM" option and tell it which kind.
It takes a while to generate these, so you will get an email with a link to download it once its ready...
10/12/2011 at 10:06 PM
Donald is a Pro so he can go to a Profile and do that.
For Basic Users, the only way is to click on "Family" Tab at top of screen, then click on "Share Your Tree", then click on GEDCOM EXPORT - you still get many choices - including the rather recent opening of Forest to Basic users (it was only available to Pro), but you cannot Export from a Profile.
There is a statement on the Gedcom Export page saying you can go to any Profle you can edit and export a Gedcom - BUT this became true only for PRO ages ago, and they just never changed this - definitely an unnecessary teaser. I am Basic, I just checked - when I click on "Actions" on a Profile there is NO "Export GEDCOM" option (tried my mother, a grandparent, plus more distant folks - not there!!)