Gosh I've "run into" Google products unexpectedly twice now this week.

Here's another: Google Base

I've searched for a site that lists all their beta projects but am not finding one. I'd guess there are dozens or even scores. Anyone know a source that lists all their beta projects?

I don't have a list of their beta things, but I do have an account with one of their projects. It's called Grand Central. Pretty much you pick a phone number that is available in your area. Then you set up your work, cell, and home phone into it. Here are some of the features:
Screen Callers- Know who's calling and screen unknown callers
ListenIn- Hear why someone is calling before taking the call
Call Record- Record calls on the fly and access recordings online
Block Callers- Unwanted callers won't be able to reach you anymore
Notifications- Receive voicemail notifications via email or SMS
Ring Different Phones- One number that rings different phones based on who's calling
Greetings- Personalize your voicemail greetings by caller or group
RingShare- Go beyond the ring and choose ringback tones for your callers
WebCall Button- Let people call you from a web page without showing your number
CallSwitch- Switch phones in the middle of a call
Click2Call- Call from your addressbook and save your typing
Mobile Access- Visual voicemail for your mobile phone
You can also call out from your computer, but I think it costs about three cents a minute. It's still in its beta stage and you must have an invite to make an account. I have a couple invites left I think, so if anyone is interested, PM me your email.

Haha, I ran into that just yesterday - and am all set up. It's very cool.

Yeah, I actually haven't even got the chance to use it yet, but I think it will come in handy one of these days! :)

There's labs.google.com for some of it but I see that Wikipedia has a lot more of them, including GrandCentral and Base:
List of Google products - Wikipedia, the free encyclopedia

More Google Products

And

Google Labs

Google kicks

Not beta but tells me I need a website now
https://www.google.com/adsense/login/en_US/