Peeing standing up would be the biggie. There are devices to allow women to do this nowadays but I've never used one and these things are never going to be as good as the real thing. It just seems so much more convenient, standing up, whipping it out, peeing, whipping it back in again. I wonder how men would cope with peeing like a female, especially after a night out at the pub on the long walk home when trying to find a suitable bush to pee behind. Or in the pub, for that matter. It can be
excruciatingly painful standing in line for the women's toilet after a few drinks - especially on a Friday or Saturday night

Not to mention the frustration of getting there to find the cubicle you're in is either blocked or has no paper (always take spare paper!).
Waking up with a hard on would be an experience. Waking up to a blow job would be another. If I had a dick for a day, I'd wake up uncut, play around for a while, get circumcised (healing, of course, within minutes), and then play around some more and compare the sensations of each.
Like Coaster and Lord Snow said about playing with boobs, I think I'd sit around wanking for much of the day! lol I'd have to cyber with someone, too. Getting off and cumming in front of a computer screen seems so much more simple for a guy than for a woman.
I would love to feel what a guy feels just as they're entering a woman, and how different it feels when thrusting hard and deep, compared to slow and gentle. So I'd probably find several people to try this with. I've always felt a certain amount of 'guilt' (maybe not the correct word), if I've slept with someone too soon after meeting, due to it being drummed into me when I was younger than it was a bad thing. I wonder if my mother would have been so bothered about this is I were male. I seem to think not, so I'd go have lots of guilt-free sex with lots of women
Dick, if I could lick myself without throwing my back out of whack I'd never get a thing done!