Mrs.
If you're considering the campsis trumpet vines, please reconsider, they will in time take down your arborvitae and spread to the ends of your property! They are also not the hummingbird magnet the companies that sell them make them out to be. They get an occasional visit here from the hummers but not the swarms you'd be led to believe.
Other than climbing hydrangea which would need a strong support I'd use something like passiflora incarnata, or incense. Maybe even annual vines like cardinal climer, the hummers love them here in New England.

Hi Mrs Ravenholt. I don't know how well they grow in Seattle, but I've had great luck with my yellow alamanda. It's taken over my fence and grown half way up a nearby Palm tree.

They have to be trained though. They're not like vines that have suckers or climbers or whatever they're called. You can see a picture of it at the link below.

Take Care,
Dee

Here is a link that might be useful: Alamanda growing like crazy!

Hi again Mrs Ravenholt. Here's a picture of the Alamanda I referred to in the previous post:

If you have any questions, don't hesitate to ask.

Dee