I attempt to test and write reviews on this blog for as many devices as I can, but I do have a limited budget and available time so there are lots of devices I can't test out. You can view many reviews and videos of mobile devices on YouTube as well, which is a great help in giving you a feel for each device. Dave sent me some information on a new site that provides virtual devices for you to actually try out yourself, including hardware button presses and more. TryPhone currently has four models for you to try out online, the Apple iPhone, LG Muziq, Samsung Juke, and BlackBerry Pearl.
If you don't have a local store in your area to try these out yourself or you didn't get to try all the features because the battery was dead at the store, then I think this site is a great idea that may help you take a more extensive test drive of a device you are considering. Some devices are not even available at local stores and these types may appear on TryPhone in the future as they are planning to continuously add new devices.
I personally plan to use the service for myself since they also provide device specs in a nice format. Their service also has reviews, tutorials, and demos of the devices. You can also send feedback on one of the virtual devices or request that they add a new phone to their offerings. I look forward to seeing this site continue to grow and have it now bookmarked.