Akiko writes, "I was waiting for approval of my employment based green card petition but I have since married a US citizen. Should my husband also file a family based petition for me because my understanding is that it will be approved faster?"
Yes, that is exactly right. As long as you do not mind spending the money, doing the paperwork, and going through the medical checkup, nothing stops an immigrant to file multiple immigration petitions. You must also remember that in a marriage based petition, you will have to answer difficult questions related to the validity of your marriage and your permanent resident status will be conditional. After two years, you will then need to do additional paperwork to prove that you are still married. In case you get divorced in the meantime, your green card will be in jeopardy. On the other hand, in an employment based green card, there will be no conditions. So unless you expect your employment based card to take unusually long, that would be a better option.
Since you will list your A#, the USCIS will know that you have multiple petitions. Generally speaking, if one of your petitions is approved, others become invalid automatically, but you must still write to the USCIS after approval of your green card to withdraw whatever petition is pending.