While Google did not disclose the number, as usual, we can always find pieces and use our imaginations to think beyond.
There's a photo on Flickr says "joe(Joe Kraus) sez: i’m holding out one finger for every $10M Google paid for Jot… but they’re in my pockets ;)"
10*10M=100M. There we go.
http://www.flickr.com/photos/500hats/293102318/
http://googlified.com/2006google-paid-100-million-for-jotspot

We can't see how many fingers he's "holding out". Could be 1, 2, 3, ... We have to guess!

He has 10 fingers in his pocket though. :D
Well, at least we know it's more than $10M.

I heard the grab was initated at 40M

Photo caption:

"Is that 4 fingers you're holding out in your pocket or are you just pleased to see me?"

;-)