Awesome chart by CNET News.com about Microsoft past Acquisitions in last 11 years.
| Company | Year | Estimated cost |
| Fast | 2008 | $1.2 billion |
| Aquantive | 2007 | $6 billion |
| Tellme | 2007 | $800 million |
| Navision | 2002 | $1.33 billion |
| Great Plains | 2001 | $1.1 billion |
| Visio | 1999 | $1.3 billion |
| Hotmail | 1998 | $400 million |
| WebTV | 1997 | $425 million |
| Source: CNET News.com | ||









Add..
1. Farecast
2. Komoku
3. Danger
4. Multimap
There are more which are missing in the list… You can find more web2.0 acquisition at: http://i-stuff.blogspot.com