This is a rather long clarification of the access control system that the MOB is using.
The childcare list is a protected document hosted by Google, you can make copies and send them around, but IMO, it's better to keep an online version and require people to log in to view it. You must log in with a Google Account in order to view or edit the list or edit the MOB site. This is just a fact of life on the internet today. If we had protected content hosted by Yahoo, you'd need a Yahoo account, same for Facebook, Microsoft and so on.
The MOB list and Google Accounts.
There are two ways to sub the list: by sending an email, or via the Google Groups web interface. It is possible to subscribe to a Google groups mailing list (like the MOB list) with any email address. This will deliver the mail to your mailbox. However, to use the web interface to the group you must log in with a Google account that has the same address as the one subscribed. The childcare list is available only to those that have a Google Account. The content of the list is not public, I think for good reason.
A Google account is not necessarily a @gmail.com account. In fact, less than half the Google accounts are used with Gmail. You can create a Google Account for any email address. Create one for the email address you subscribed to the MOB list here https://www.google.com/accounts/NewAccount or you can use an existing account and sub that to the list. Having a Google Account does not mean Google is handling your email. It just lets you log into iGoogle, Picasa, Checkout, Reader, Docs, and so on.
Many of you have a Google account with the email address that is subscribed to the list. Some of you don't.
For the former group, you can sign in to any page on Google.com with your MOB list email address. You should have access to the web interface for the group when you are logged in as well as read access to the childcare list. If this is not the case, something is broken.
For the latter, you can either create an account with that email address or continue to just be in 'email only mode'. I strongly
encourage you to create an account that corresponds to the address you're subbed with.
You should be able to make the account no matter what your email address is, no matter how you get email.
The account doesn't set you up with Gmail or require you to use it for anything other than MOB stuff.
Hit the 'sign out' link in the upper right hand corner of any page on Google if you don't want to be signed in to Google.
I admit it's very confusing, since you're able to sign up for an account with email addresses from another email provider such as Yahoo. There is not a one-to-one connection between email addresses and accounts. Your email address in this case is really just the account name or user name you've chosen.
Here's some more info