It's been 3 months since we launched our startup and it's has very little traction. What are some ways we can market it without using any money, just our time.
Some things we have on the whiteboard:
Here are some of the best no-cost things from a longer answer of mine on Quora about how startups can initially draw attention to their product.
Everything that I see you've listed from your whiteboard is very generic ("contacting blogs", "popular blogs", "popular meetup groups"). Relevance is much more important than reach. Marketing is all about identifying audiences and either reaching them with a message or drawing them in with value. Really good marketing is about being a member of those audiences yourself, and being able to talk with them as a peer.
Even if you're a mass-market consumer web service, you can't boil the ocean as a startup. Choose a specific niche to focus on first, get enough traction there that it grows within that niche on it's own, and repeat. That's how Facebook, Yelp, and Twitter all did it.