My suggestions would be to utilize reverb at http://reverb.echo.nasa.gov/reverb/. First register if you have not already done so. In the search box type ASTER GDEM and Select Dataset --- note if you want a particular area this is the point where you select the box range in the map window to the left (very useful feature!).
ASTER GDEM Global Digital Elevation Model V002
Select "Search for Granules"
Now begins the tedious part where there are over 22,000 ASTER GDEM tiles that cover the globe however, the website only list 400 per page where there is an 'Add All on Page' button but no Add All option (i.e. 50 + pages to go through + load time).
Press the View Items in Cart (Shopping Cart), press the 'ALL' button that will pop up a new message 'All Items on Page Selected. Select All n Items in Cart'. Click on that link. At the bottom of the page select 'Order Selected' (no direct download is available).
Follow the appropriate steps including your order details (its free no worries) and on the following page select the 'Order Option - Not Set and Required' button to state the reason for the download (remember to use the apply to all function).
You will then receive an email entitled CM SHARED with directions for ftp pull on your selected data. From my limited experience, this usually takes approximatley one working day. Essentially the ftp and pull directory to connect will look like:
ftp://e4ftl01.cr.usgs.gov # Ftp Server
PullDir/0302595257dmDDFH # Pull Directory Example
This provides really fast download (unlike some other ftp sites Global Land Cover Facility) especially comming from Europe (5mb/s).
Sorry for the long answer to a rather simple procedure but as I write this I am actually downloading ASTER GDEMv2 data myself for the entire continous USA. Note ASTER GDEMv2 is not void filled (although improvements have been made), unlike others like SRTM V4.1 from http://srtm.csi.cgiar.org/ at 90m resolution.