And the winner is....

It's a challenge...
Criteria:
1.  Portable
2. Interesting
3. Mindless
4. Useful

Socks?  Lately  I've been making such complicated socks that I'm never sure if they are going to be "keep your eyes on the chart" interesting or repetitive enough to be a challenge yet not boring.

Kristi - Keep your eyes on the chart

Sunshine - repetitive, not boring

After I'm more than halfway finished with the first sock, I make that determination.  Therefore, I rejected socks.  I didn't want to take one halfway finished... I might run out of knitting.
Shawl? I looked at other, longer, half completed projects and came so close that it actually touched my carry-on:

Europa Shawl - well traveled

It certainly is light-weight, and has traveled across the Pacific Ocean (twice). But I never feel relaxed while knitting this, especially on open water... plus there's the chart holder, and the charts (2 more needed) and chart C is a two page'r taped together... so I decided it's not mindless enough. (It appears that I'm approaching a section of no nonsense knitting, but I can't risk it.)
Instead, I cast on (to check gauge) a little something I had put on my Ravelry project page with "zzz" attached.  Yes, this will work.  And my bag holds all the accessories.  Yes, the clear jar (plastic) is going in my carry-on.
The winner: Girly
For a little girl. <3

Pattern: Girly by Mags Kandis from Mission Falls Wee Knits 3

Yarn: Cable Cotton by Elsebeth Lavold Aran / 10 ply 100% Cotton 93 yards

Link to my Ravelry Page