I like the third and fourth. I have a project that I can pay you $5 for a rough-draft, conceptual idea (if your available). PM me if you want to learn about the project. The entire budget is just $20 maybe a bit more.
Great designs here, they are professional and definitely well thoughtout. Congratulations on the work!
Nice work! Some people have the knack for doing logos/marks, and others don't. I fall into the latter category. I think you have some great work! And since you asked for a critique... The Ecolife logo is nice, but I think the font is a bit too heavy and thick for an environmental-themed logo. I would think that something thinner and lighter would work better. Just my $0.02... Anyway, good stuff!
Thanks for the nice comments my friends. About the EcoLife logo; I made that for a client on oDesk and he rejected my candidacy even before i could show him my logo.