1. Ziploc Bags -- Male. They hold everything in but you can see right through them.
2. Copiers -- Female. 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. Tire -- Male. It goes bald and it's often over-inflated.
4. Hot Air Balloon -- Male. 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 -- Female. They're soft, squeezable and retain water.
6. Web Page -- Female. It's always getting hit on.
7. Subway -- Male. It uses the same old lines to pick people up.
8. Hourglass -- Female. Over time, the weight shifts to the bottom.
9. Hammer -- Male. It hasn't changed much over the last 5,000 years but it's handy to have around.
10. Remote Control -- Female. You thought it'd be male. 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.