I have an Inglesina Swift w/ mac organizer. Fits small water bottles fine, not really any other drinks. I have the Valco cupholder, I LOVE it, it fits a fountain soda w/o problem, and the stroller folds w/o problems. I have this little bag called a jym baggy that you really snap onto a treadmill to hold a walkman(back in the day, lol), and I attatched it to the side for a little saddle bag, I'll have to test this out. I have the Carry You little bag--I'm not sure what it's called but it holds a sippy cup or cell phone, down by ds's seat, he keeps his sippy in it.
I love the idea about the wrist wts, I'm going to check that out. My mom likes to use the stroller as her personal stuff-holder, drives me crazy, but I'm sure it will be tippy.