Change a blog name

Q: How do you change a blog name?
A:  Blog name and blog address are not the same thing.

Change blog name (title)
Please go to settings>>basic>>title.
Make the changes.
Save settings

Change blog address (URL)
settings>>publishing>>Blog*Spot Address
Make changes inside the box.
Save settings

However, please be aware that changing blog address may have adversed consequences:

You may lose 

1. all your followers

2. your blog's established Google ranking

3. adsense earnings
4. feeds
5. domain connections
6. backlinks

source: http://www.google.com/support/forum/p/blogger/thread?tid=6349d53c6da7f902&hl=en&fid=6349d53c6da7f902000474c2946c31ba