Mobile devices are the frontier for malicious hackers and other technological ne'er-do-wells, which means that the Android operating system sheriffs can't be far behind. It's an unusual space to be in at the moment, because while malicious mobile apps have been proven to exist and indeed are legitimate threats, there's very few of them for one simple reason: there's no money in it. At least, not yet.

You can bet your last horse bound for the glue factory that as phones replace credit cards and are increasingly used to conduct transactions, the threats will increase. App makers aren't waiting around, either, and already there are some major Windows security players moving into the Android market. Many of them don't have fully baked, stable releases, but some do. We've reviewed three of the better-known apps that are ready to safeguard your phone: AVG Antivirus, Lookout Mobile Security, and Trend Micro Mobile Security. (Check out our comparison chart.)

Generally, these three compare favorably against each other, although there are definite differences. DroidSecurity was the original publisher of AVG's app, and so the look and feel of AVG Antivirus for Android has very little to do with the desktop application. Expect that to change in the coming year, but for now they seem to share only a company logo.

The features in AVG's app are similar though not identical to Lookout's app. Lookout has been garnering massive attention in the Android world, to the point where it's been featured on several Android television commercials. The app has more going for it than a good PR firm; Lookout has been developing its App Genome Project, a real-time database of verified legitimate apps and their security implications to further bolster the Lookout app's bonafides.

AVG and Lookout share common features beyond their scanning tools. Both have a lost phone locator, a must-have feature for mobile devices, although the implementation is different between them. Lookout's implementation feels more polished thanks to a stronger Web site design, and where Lookout offers an on-demand car alarm-style "scream" deterrent, AVG lets you send custom messages to the screen. However, AVG's remote lock and wipe are included in the free version, which Lookout reserves for its premium customers.

Both also offer backups, again with different implementations. Lookout restricts content backup beyond contacts to premium users, while AVG users get free access to backups for text messages, bookmarks, system settings, application settings, call logs, as well as contacts. Despite fewer features being offered in the free version, Lookout's implementation is preferable for several reasons. One is that AVG's backup covers much of the same ground that other free backup utilities or options can help you with, such as contacts and bookmarks, without backing up many people's most prized possession: their photos. Settings and text backup without having to root the phone is an excellent feature, though, and so I'd place the two apps on equal footing.

Trend Micro stands slightly apart from AVG and Lookout. It doesn't have a phone locator service, although it does offer parental controls and a solid call and text message blocking system. It also ports its Smart Protection Network from the desktop to the phone, running Web sites you look at in the default browser through a safety check without slowing down your device. Unfortunately, the SPN doesn't yet support other browsers, such as Dolphin, Firefox, or Opera.

Another difference with Trend Micro is that it's not free. Like the desktop version, you get a 30-day, unencumbered free trial, after which a license costs $3.99. Upgrading AVG will set you back $9.99, while Lookout Premium commands a premium of $29.99 per year.

All three will enhance the basic level of security on your phone, and all three have strong added-value features. However, when it comes to app verification and lost phone locator implementation, my two biggest concerns, Lookout jumps to the top of my list.