QUOTE(languageladki @ Jul 1 2006, 06:51 AM)

My question is this: if my husband does file the I-129, when can he come to the U.S. and will he be able to work immediately? Can the EAD be filed with the 129 or only after approved? Also, can he travel back and forth liberally between Canada and the U.S. once the 129 is filed (for work and visiting his elderly mother)? I've tried to read all help guides but am still mega confused. I don't know whether we should continue waiting for approval of the 130 or proceed with the K-3. Any insight would be helpful. Thanks
Your husband would not file the I-129f, you would. You must include a copy of your receipt from the I-130 filing.
If that petition is approved and is sent to the Consulate before the I-130 (this is not a sure thing), then your husband will be invited to apply for a K-3 visa.
When he arrives in the US, he will not be able to work immediately. A K-3 has no employment authorization and may not apply for it until he is in the US (see form I-765). Once the EAD/Employment Authorization Document is issued, he can apply for a Social Security number. Considering the time to apply for an EAD and receive a SS#, your husband should plan on not working in the US for about 4+ months from application.
As a K-3, he can travel freely on just that visa for the validity of the visa/status (2 years).
There is some question about working abroad while a K-3; you might want to consult with an immigration attorney to find out if working in Canada is a possibility. No one here has ever successfully answered that question.
If the K-3 doesn't really suit your needs,you are probably better off waiting for the 'right' visa option. An immigrant visa (CR-1 from the I-130) is the Full Meal Deal, with residence, work and travel permissions included.