If you want to get all your contacts in gmail along with the groups they are in that you may have created in gmail, check out this app - it's worked quite well for me.
Only issue is it does not yet sync - you need to overwrite the ipad contact with your gmail ones. I just make sure to enter any new contacts into gmail first, then do a sync a few times a week to the iPad.
When it asks, chose Merge to make it all one database, or Keep if you want to keep the contact you entered on the iPad and the GMail contacts separate.