Explain first what do you mean by "the hell out of blogspot blogs". Any range for that phrase?
Each free blog MAY be hosting on a different IP but in some cases, it is on the same IP. It is perfectly okay to do this but keep in mind that you have to keep it as a PART of your SEO plan and not only your source of backlinks.
Why? Because if you keep doing this, you may be forgetting the fact that the majority of these mega free weblog sites are being moderated which means that a single footprint can easily wipe out all your backlinks. That's why it is very dangerous to keep on backlinking to your site from a single weblog or from two different sources.