I am a Sherlock Holmes nut. Sadly, however, my hero has rarely mixed his sleuthing with my other passion, horses (with the exception of frequent horse-drawn taxi rides, and the case "Silver Blaze"). Thus, I was delighted to find that the latest cinema twist on Holmes, "Sherlock Holmes: Game of Shadows," featured quirky Robert Downey Jr. riding a tiny Icelandic horse, after refusing to mount a full-sized equine. "They're dangerous on both ends and crafty in the middle," he declares. Very true.
The pony (ahem, sorry, small horse) he rides seems very small, even for an Icelandic; I suspect they used some camera or costuming trickery to heighten the comedic affect. Icelandic horses are usually around 13 hands tall; small, but not Shetland-pony-sized. They are, however, quite strong, so the idea of a full-sized adult riding one is entirely accurate. In fact, they're often preferred by adults because their smooth, super-speed trotting gait (called a tölt) is so comfortable. Apparently it's so smooth that you can ride at that pace whilst holding a full mug of beer and not spill a drop; but don't take my word for it, just watch this little educational clip: