I'm biased, but believe that -- if you can swing it -- biking is absolutely the best way to navigate the streets. That being said, conscientious riders are pretty much always going to be stuck toting two things around at their destination: lights and a helmet. The former will likely get swiped if accidentally left on; the latter is just plain clumsy, and not ideal to leave outdoors when the weather's nasty.
Enter HelmMate, a clever solution from a new Danish brand that wants to keep your noggin safe forever and -- bonus! -- your butt dry on rainy days. It's a small case that attaches under the back of your seat; inside is a water-resistant cover. Once you're locked up? Unfurl the nylon sack and hook it beneath the front of your saddle; put your helmet inside, zip the whole thing up, then use the teensy combo padlock that's included to secure the zipper tabs. On rainy days when you're ready to roll, you won't need to do the old sleeve-seat-swipe to ensure your pants don't get wet.
It's the latest in a series of new designs making the helmet less of a conspicuous pain -- see the foldable model, and the crazy inflatable Hövding which also addresses the issue that helmets, despite their ability to protect your damn brain, are still viewed as uncool by so many folks out there.
On that note, check out these two attractive foreign men introducing and demonstrating HelmMate's functionality. If they can get on board with helmets, you can too!