1. Make sure you do the Hilton "profile update". You can get 1000 miles each time and this can be done twice. After 7/1/02 you can do it again for another 2K miles. Grand total 4K miles for doing nothing.
2. Just because Alaska isn't one of the majors doesn't mean you shouldn't consider them. Dont forget that as an Alaska member you can EARN and REDEEM miles on many airlines: AA, Qantas, BA, CO (for a limited time), etc. Check the alaska link above for more details and to verify the nature of the partnerships.
3. CO is a good domestic airline but for travel to the left coast, its horrendous. You will end up connecting in IAH for every trip. CO also has a huge chip on its shoulder lately with customer service last on its list of priorities. Gordon Bethune routinely lies to its best customers (elite members). Finally to top it off, the international upgrades on CO are pathetic. Almost impossible to get an upgrade to biz class without paying full fare. Virtually impossible to use miles to upgrade, and even less chance of getting upgrade seats when available. To top it off, CO employees (non-revs) can get biz class seats VERY easily due to this stupid CO international upgrade policy. For a good laugh, goto the CO board and do a search on "Hokey, BendForward, 72 Hour rule, 30 day rule, EUA" and you'll see what I mean.....stay far, far away from CO.