Latest Gmail developments and concerns:

-- Google has now invited its AdSense advertisers to try Gmail. That's an additional minimum 60K more users into the system, which is still invitation-only, but indicates the company continues to expand the testing-user base slowly but surely. We just got our next round of invitations to hand out. Anybody want one?

-- Google's obviously not deduping its database to weed out people who get sent more than one invitation.

MarketingSherpa Publisher Anne Holland already has a Gmail account but just got invited by someone else to open one. "That's dumb," she said.

Another glitch: If you remember your user name but forget your password, Gmail can help you. If you forget your user name, you are SOL.

Now, combine that with a 9-month lifespan for dormant accounts, and you could be emailing to a dead account (but a live address) for 9 months.

There is a workaround -- Gmail automatically puts the email address of everyone who accepts your invitations into your contact list (along with everyone to whom you've sent email from your Gmail address. That's a bonus for whitelisting). So you just have to track down the person who sent you an invite to see what address they have for you. Not that Gmail will tell you.