Android may be a versatile OS, but the little green robot can run into trouble when it comes to certain file formats. RAW photo formats such as .NEF won't show up in the default Android's image and video Gallery app. Even common video file formats such as .AVI and .MKV will stop most Android phones in their tracks.
Luckily, there are apps and workarounds so your Android phone can open most audio, video, image, and Office file formats you throw at it. Being able to playback a myriad of file formats is good because not all file formats are created equal. RAW images, for example, tend to be of higher quality than standard .JPEGs. And .MKV files can play videos with subtitles--helpful if you are hard of hearing, watching a foreign film, or stuck on an airplane with crummy headphones.
Also, by making your phone accept a more diverse number of file formats, you can save yourself the hassle in converting your media files into (more often than not) inferior and more common file types that aren't as good at reproducing hi-fidelity music, saving storage space, and displaying crystal clear images.
The default Android media player is very picky about what it accepts if you try to load it with anything other than .MP3s. For a better audio experience, look no further than the PowerAmp Music Player. The list of formats that PowerAmp can play includes .MP3 (of course), .MP4, .M4A, .ALAC, .OGG, .WMA, .FLAC, .WAV, .APE, .WV, and .TTA. Besides accepting a wide variety of audio formats, PowerAmp is customizable with several themes and comes with a handful of widgets to choose from. PowerAmp costs $5 for the full version, though there is a free 15-day trial as well so you can try it out before you buy.
If you don't feel like spending $5 on an app, you can also try out Mortplayer Music. Mortplayer (free) can handle all the same formats that PowerAmp can, though the interface is not as clean as the one in PowerAmp and it cannot play .FLAC files on all devices.
While Windows Phone 7 phones may be the kings in handling Office documents, Android also can juggle work documents (Word, Excel, PowerPoint, and Adobe) with ease. All Android devices by default can view Office documents, but you will need a separate app in order to edit and create new ones. There are quite a few mobile office apps to choose from; it really boils down to what features you want.
I personally prefer to use QuickOffice ($15) because it can sync my files with my DropBox or Google Docs accounts. Chances are your phone came pre-loaded with the trial version of a mobile office app. Much like with PowerAmp, I would recommend playing around with a trial version before committing $15 for an app that doesn't have the features you want.
One workaround is Google Docs, Google's online service for creating and viewing office documents. The official Docs app does a sufficient job at displaying your documents. However the app has issues with keeping document formatting, so I would not recommend using it to create or edit your work. Results may vary on your Android phone or device. For all other text formats, the best and easiest workaround would be to e-mail the document to your Gmail account, then view the document using the "Preview" option inside your Gmail message. You may not be able to work on it, but at least you can read what the file says.
By default, the Android Gallery can handle most standard image formats (.JPEG, .GIF, .PNG, and .BMP). Unfortunately after searching the Android Market, I only found one app that allows you to view images in the RAW format. The app is called RawDroid (free) and is currently only available as a demo, though it allows you to view images in formats such as .NEF and .CR2.
For Adobe Photoshop users who live and breathe by .PSD files, as of now, there is no apps solution for viewing that file format. Even Adobe's own Photoshop Express application wouldn't recognize the ones I loaded onto my phone's SD card. Hopefully Adobe's Photoshop app is updated and .PSD formats are supported in the future.
Trying to format videos so that they work on your Android phone can be a nightmare. Until the VLC player comes to Android, you'll have to look elsewhere to find an app to play your HD files. The desktop client DoubleTwist can convert your videos into a format that natively works on your phone. Run the program, and plug in your phone. DoubleTwist should recognize it. From there you just drag and drop the media you want put in. While helpful, DoubleTwist can be extremely buggy at times and is known to crash randomly. Still, it is the easiest and best way to put playable video files onto your Android phone.
Another advantage DoubleTwist and VLC have over the stock video player that comes with Android is that they support video bookmarking. That's an important feature if you are watching a video longer than 20 minutes. Bookmarking allows you to stop and start the video in the same place. That beats having to scroll through a video to find the spot you think you stopped watching the video.
Having a device that works seamlessly with a variety of file formats allows you to get the most out of your digital life and your Android phone. P.S. It can also save your bacon when your boss wants you to proof a work document.