I love the Droid so far but don't like how contacts are listed as one long list and going through settings each time I want to change groups is annoying to me. I have a kind of workaround that's not very elegant but does what I want.
Find some empty space on one of the home screens. Long press and select "Add to Home screen". Select "Folders". Select "New Folder". Open your new folder by pressing the folder icon. Long press the open folder's title bar. Give it a name, like "Work contacts". Then you're back at the home screen again. Long press on an empty spot again and under "Add to Home screen" select "Shortcuts". Then select "Contact". Select the contact you want from the contact list it brings up. You're back at the home screen again. Long press on the contact you just added there and then drag it onto the folder you created earlier. You've got a group folder with the contacts you want in it.
Again, not an ideal solution but it works ok if you don't like the Droid's current system or any of the contact managers available right now.