BTW: I arrived on an E3 then was successful in moving to a H1B this year, shortly after the H1B. Coincidentally within a week of the H1B effective date I proposed to Nicole, so now I'm engaged to a US citizen, and I can pursue a green card through marriage or through employment. I'm actually doing neither right now: I'm currently intending to stay on the H1B for a while. A green card has benefits - easy ability to change employer - but also has drawbacks - such as once you have held a green card for (I think) six and a half years, if you leave and ask for your green card to be canceled, you are treated as a departing citizen (the implications of this were very recently changed, and now include a mark-to-market on your worldwide assets, some tax implications in the order of 15% for your 401k, and all gifts to US citizens being subject to gift tax for the rest of your life without the normal exemption level).

The green card process takes in the order of 9 months, without taking into consideration deliberate delays (quotas etc), whether it's an employment or marriage green card. For a marriage based green card, it becomes permanent in one of two cases: if the processing completes before you have been married for two years, it becomes permanent two years after processing completes; otherwise, it becomes permanent immediately. So, if you want a permanent green card, then the fastest way to get one is to apply for the green card after being married for 15 months. However if this processes just a little too quickly, you could end up having to wait for four years before the green card is permanent.