Limitations and Important Notes
As cool and simple as the HP Video Converter is, it's not perfect. There are a few things you should know, as well as a few cases where a few extra steps may be required in order to get things working properly.
Why are HQ files so large?
HP's Video Converter attempts to maintain quality as close to the original as possible, and therefore typically uses a similar bitrate as the original file, or so it would seem to me after comparing some originals to the output files. This means converting things like DVD VOB files will result in file sizes similar to the DVD. That's not exactly ideal if you're trying to conserve space.
If you're looking to save space, and your home movies are already in DVD format, I suggest using a different tool to convert your DVDs to video files. There are many that will work, but Handbrake is a free and popular choice for converting DVDs to H.264 files.

It gives you a lot of flexibility over your encoding options and can help you maintain a better balance between video quality and file size.
Why do my widescreen videos appear squeezed when viewing on my TV or when viewing remotely with Media Streamer?
If you have a camcorder that shoots in anamorphic widescreen, you may experience some problems viewing your home movies in the correct aspect ratio. Sometimes you'll have problems with both HQ and MQ versions, and other times only have problems viewing mobile versions with Media Streamer or on a mobile device. This will vary depending on the model camcorder you have, and how your videos are currently stored.
To overcome this, there are several options. If you're experiencing problems viewing widescreen materials on both your TV and the mobile streamer, there are some things you can do to overcome this, depending on how your movies are currently stored.
If you currently have your movies on DVD, try using another tool (like Handbrake as listed above) to convert your video. They may be better at detecting and compensating for the aspect ratio.
If you imported your movie file into Movie Maker, you can output your movie in a format that takes the widescreen proportions into account. First, go to Tools --> Options --> Advanced, and make sure 16:9 is selected in Video Properties. For the best quality results for your HQ version, select "Save Movie..." in Movie Maker, then choose "High Quality Video (NTSC)" from the drop down list. Take the resulting output file and convert it with the HP Video Converter. It should appear in widescreen on TVs and Extenders.
For the MQ version (or if you're still having problems with viewing widescreen content on your TV), follow the steps above, except choose "High quality video (large)" from the list. This will save off a WMV file at 856x480. Convert this file in the HP Video Converter, and all should be well when viewing on a TV, mobile devices, and through the HP Media Streamer.
I have a High Definition camcorder. I can view my movies just fine on my TV, but I want to stream movies to my iPhone using the iStream App. What do I do?
As noted above, the HP Video Converter doesn't currently handle HD video in any format. Your camcorder should have come with software that allows you to edit HD video. This software should also let you save standard definition versions of your home movie.
If your software allows you to save a mobile quality MP4 file, the output files should work just fine with iStream. However, if you have trouble, save off a copy your home movie in standard definition using a format like XViD or WMV. Then, drop that resulting file in your conversion folder to make a mobile quality version using HP Video Converter.
Wrapping up
There are several more ways to skin a cat, though I've found these directions to be pretty reliable and easy to follow for most who are getting started in the world of video streaming with their MediaSmart Server.
Of course, if you have alternative methods that work for you, share them in the comments section below.