On a slightly serious note here, I've been using shedinja somewhat. Provided you keep the weather in your favor and hazards off the field, shedinja is the perfect pivot switch pokemon. With team preview in Gen V, he just became possible to use.
He's also a perfectly viable spin blocker. What can Starmie possibly do to shedinja? Trick? It can't spin nor can it harm with any attack it would normally carry. It never carries power gem. Forry can't harm shedinja either. Unfortunately, the likes of Hitmontop and Donphan are another story, but most Donphan carry ice shard over stone edge, so you're fine there.
Another thing about shedinja is that he is the perfect bait. If anything at all that isn't a weather user decides to switch in to shedinja, then it can kill shedinja. This lets you know a little bit about your opponent's pokemon's movesets. If a Vaporeon switches in to shedinja, then its probably carrying toxic. Hell, this can even tell you what type of hidden power your opponent may be carrying if they aren't actually carrying toxic. I once had a lightning rod Zapdos switch in on my shedinja. Knowing it didn't have Heat Wave, I naturally switched out anyway. Zapdos actually used Ancient Power on me...
Shedinja's weaknesses can work to your advantage, if only for making your opponent easier to predict. A good player isn't going to let shedinja run rampant if they can dispose of him. If they don't want to reveal a moveset, then they'll switch in a hazard user (usually Skarm or Swampert), set up, and try to phase you.
After eliminating pokemon who can kill shedinja, shedinja can show his value late, late game. Even if your opponent is trying to play to the point where they can keep at least one shedinja killer around if your shedinja is still alive, I don't think they'll constantly like switching it in to several attacks repeatedly when you bait with your shedinja over and over again. Besides, it's shedinja. Since when does anyone deliberately pack counters?
Personally, I run Sword's Dance, Shadow Sneak, Will-o-wisp, and X-scissor. Adamant nature and 252/252 in Atk and speed. Not saying that shedinja is invincible and has no problems, but he isn't a total joke. How often do you see Flareon boldly switching in on Kingdra and forcing them out?