I was just in Seattle, and here's a photo of what I was up to on the ferry from Bainbridge Island.
Get it? Knitting needles? Space Needle? But here's the question: do you designate which of your projects goes where?
I myself like to have three projects going. First, a complicated project that isn't going to leave the house unless I expect to have some serious time and space to devote to it in another location. I have an Orenberg shawl with a ginormous chart going now that fits that description.
Second, a medium complicated project that is appropriate to take to a knit night, or have on a plane, things like that. My current project that fits that description is my pair of snail mittens, which only need thumbs completed and ends woven in at this point. (Weaving in ends has become a favorite knit night activity of mine because the act of being at knit night has an ameliorative effect on the perfect torture of end weaving.)
The third is stockinette socks. It's a new policy as of this year to always have a pair of these on the go, but it's quite effective. Three pairs completed so far this year and into my fourth. I finished a pair at a Yankee game last week.
Between the rather lengthy bus ride between the school I work in and my office, time spent waiting for the subway, and time spent riding the subway, there's quite a bit of sock knitting time in a week. Add in an Audible subscription, and it's pretty much awesome.