1) Ziploc bags are male, because they hold everything in, but you can see right through them.
2) Copiers are female, because once turned off, it takes a while to warm them up again. It's an effective reproductive device if the right buttons are pushed, but can wreak havoc if the wrong buttons are pushed.
3) A tire is male, because it goes bald and it's often over-inflated.
4) A hot air balloon is male, because to get it to go anywhere, you have to light a fire under it, and of course, there's the hot air part.
5) Sponges are female, because they're soft, squeezable and retain water.
6) A web page is female, because it's always getting hit on.
7) A subway is male, because it uses the same old lines to pick people up.
8) An hourglass is female, because over time, the weight shifts to the bottom.
9) A hammer is male, because it hasn't changed much over the last 5,000 years, but it's handy to have around.
10) A remote control is female. Ha! You thought it'd be male, didn't you? But consider this - it gives a man pleasure, he'd be lost without it, and while he doesn't always know the right buttons to push, he keeps trying!