Sure, in three different ways.
The character, race, monster, treasure and table files are all saved independently and you can copy, zip, e-mail those like any other attachment, etc.
The database itself, if you needed to move it for some reason, could be transported. Zipped I think it's under 1 MB, maybe closer to 800 kb. So if you got all of your custom data entered and wanted your group to have access to it you could (they'd dump their old db and replace it with your db -- this is presuming they have their own copy of eTools).
And finally, a guy named Davin is working on (well basically done minus a coupld of points) a program that will allow you to export and import individual database items built with the customizers (custom feats, skills, spells, weapons, etc.). It's a really sweet little program, I can't wait for folks to see it. It also has a nice "backup database" function so you can save your db before you start monkeying with it.