Coinpunk.com offers free web-based Bitcoin wallets, which you can use to quickly get started with Bitcoin. It works on all modern browers, desktop and mobile, and supports the same QR scanning functionality native apps do.
All encryption and transaction signing is done on the web browser, which means it is less susceptible to Bitcoin theft by hackers. And we're working to improve security all the time.
Like Bitcoin itself, Coinpunk is 100% open source. If you're a developer, you can add features and improvements and we'll merge them in. If you don't like how we're doing, you can run your own Coinpunk server.