From the Eide Neurolearning Blog regarding the effects of blogging on the brains of bloggers: (conclusions very briefly excerpted)
1. Blogs can promote critical and analytical thinking.
2. Blogging can be a powerful promoter of creative, intuitive, and associational thinking.
3. Blogs promote analogical thinking.
4. Blogging is a powerful medium for increasing access and exposure to quality information.
5. Blogging combines the best of solitary reflection and social interaction.
Read the whole entry (highly recommended!).