Would appreciate any help you could offer rounding out the stats below (and adding apps that I've missed that have impressive #s):

FourSquare:

• more than 600,000 checkins a day 5/17/2010 http://twitter.com/foursquare/statuses/14182296112

• more than 1,000,000 unique users 4/21/2010 http://twitter.com/foursquare/status/12585316625

Gowalla

• More than 600,000 unique location checkins http://www.businesswire.com/portal/site/home/permalink/?ndmViewId=news_view&newsId=20100310006776&newsLang=en

• Gowalla has stronger positive mentions than foursquare http://www.socialmediatoday.com/SMC/191772 and gowalla vs. foursquare http://mashable.com/2010/04/22/foursquare-gowalla-infographi/

• Gowalla users average less "friends" than FourSquare http://osnapz.wordpress.com/2010/02/15/foursquare-vs-gowalla-user-stats/

Google Latitude:

• More than 3,000,000 active users 5/6/2010 http://techcrunch.com/2010/05/06/google-latitude-users-check-in/

• More than 8,000,000 total downloads 5/6/2010 http://techcrunch.com/2010/05/06/google-latitude-users-check-in/

MyTown:

• More than 2,000,000 active users up from 500k in January 5/5/2010 http://techcrunch.com/2010/05/05/booyah-hits-2-million-stealing-foursquares-thunder/

• (From their 1,000,000 user report, doubled) 80 million virtual items consumed weekly, 50 million checkins weekly, daily engagement AVERAGES 65 minutes