Luckily for iPhone and iPod Touch users, third-party vendors are supplying applications that help fill some security holes. Acrylic Software makes software that fills some of these chinks. Its Mac software, Wallet 3, costs $20 CDN ($15.62 US); upgrades are priced at $5 CDN ($3.91 US) and requires Mac OS X 10.5 Leopard--sadly, there is no Windows version. A version of Wallet for the iPhone and iPod Touch (iTunes Link) costs $3.99 US.
Wallet for iPhone is a lightweight database application that stores your important information, such as credit card numbers, passwords, credit card data, software serial numbers, agenda, and even shopping lists. All this information is securely stored using 256-bit AES encryption, which should protect the data even from a forensics expert.
Wallet's nicest feature across all versions is that it lets you synchronize your encrypted Wallet database to multiple Macs, iPhones, or iPod Touches using MobileMe. All these devices share the same database, and sync setup is performed by completing a few minor configuration steps on each device. You can also sync directly between the devices and your Mac using Wi-Fi.
Wallet lets you do some serious customizing to meet your needs. You can complete all data entry on your iPhone and customize how your data is stored by extending group fields without any limits. You can add attachments to any record, but unfortunately only using the desktop version of Wallet. Wallet's easy search feature, which works like the one in the Apple Contacts app, finds what you're looking for quickly and easily.
Casual editing on the mobile version of Wallet will suffice, but the iPhone's lack of cut-and-paste tools makes mass editing difficult; for that, we prefer the desktop version. The desktop version also offers other powerful features not available on the mobile version, including a password generator.
If you're concerned about security on your iPhone, certainly consider Wallet, which addresses some, but not all of the iPhone's security problems. Wallet can protect your data if you entrust it with your private information, but it won't protect native Apple iPhone applications--for those, you're stuck until Apple includes encryption features in its own applications.