just another hint for doing this with pants. I'm going to try to explain it as best as I can...
if you're wearing men's pants with a fly, you don't have to pull them down very far at all. you have to pull your underwear down further than the pants. in effect, by opening the fly and lowering your jeans only about 3-4 inches, you've created a V like area to pee through (unzip your pants, lower them, and lean forward a bit and you'll get it). so what you can do is push your underwear down out of the way just enough to give "clearance" for the pee to pass over top of the V-like fly area. if youre having a problem with one of the top "flaps" getting in the way of your pee stream, you can quickly tuck it into the waistband of your lowered underwear. the more you practice this, the easier it will be to do in seconds flat. it's actually a lot less complicated than it sounds but it's difficult to describe. really, it can be done as fast as a guy can whip out his dick at the urinal once you get the hang of it. after about a week of practice in situations where I wouldn't be devastated to have an accident, I am confident enough to do this every time I use a public restroom. if your anatomy allows for it, keep practicing and you may never use an stp again.