Do you have an American Express card enrolled in Membership Rewards? If not, you could sign up for a card with a bonus of MRs. I don't know what's being offered now, but I got 25,000 Membership Reward points when I signed up for the Platinum card. You can then transfer those MR points into Continental Onepass miles.

As far as the Continental-branded Chase Mastercard goes, they've been offering some good targeted promos. Search the forum and you'll find several of the "make X purchases per month and get X bonus Onepass miles" type. Watch your mail for these targeted postcards.