Earlier US H1B holders were able to apply for Alberta Immigration (under US Visa holder category) but the rules have changed since 19 May, 2009. Now applicants who fall under NOC code: 0213 (Computer and System Managers) are only eligible (for IT workers). (
http://www.albertacanada.com/immigration/immigrate/srsvisaholder.html)
The Federal Skilled Immigration process has also changed (applicable from 28 Feb, 2008). You can qualify only if you have:
1) 1 yr. experience in 38 occupations list. (
http://www.cic.gc.ca/english/immigrate/skilled/apply-who-instructions.asp) or,
2) arranged employment offer or,
3) have been in Canada for past 12 months as a student or worker.
You can look at Provincial Immigration (they require job offer) and Quebec Immigration (you probably need to know French).