I have my contacts in GMAIL grouped as well. As far as I can tell, the groups in Gmail do not transfer over to the Droid.
I have gone over to Handcent for Grouping for messaging. Gmail on the Droid does not support preset group emailing.
Mine groups sync just fine with the droid... now that youve created new groups.. go into your droid and go to contacts and then display options and you should see your new group there "if not go sync your account first in ssttings---> accounts & sync---> pick your account make sure sync is on" now uncheck everything and make sure "my contacts" is checked.
If that doesnt work go also check at the bottom "all other contacts".
If you had to check the latter, you need to go back into your google account online and make sure all your contacts are in your " my contacts" list and not just in that one group... otherwise you wont see them unless that specific group is checked in the droid.
Believe me it works....
my main gripe is you cant create, delete or edit groups from the droid.. that has to all be done from the online google account.
Once you get things where you can see the groups in display option in the droid contacts.. then handcent will see them too.
P.S. once you get everyone assigned to "my contacts" on your online google account, you won't even need to have the checkbox checked in the droid that says "all other contacts"..... I can just check "system:my contacts" alone and I can see all of my contacts, regardless of what group they are in.
Its almost like my contacts is the main directory and the other groups are subdirectories... but you have to make sure you have it set that way by including everyone you want to see in "my contacts"
I personally created another google account just for my droid so it doesn't get all the regular spam and communication that goes on with my regular google account.
I can always sync with it too any time I desire, but I don't desire!... that keeps the droid nice and clean without tons of false alarms coming through my email.
I don't give at address to anyone and the only correspondence I do is related to the phone.... but thats just me.
You may like all the conversation of your regular email.. but I have to work and would rather choose them when I want, not when they want me.