Superjump to infiltrate Doge's Palace
http://www.youtube.com/watch?v=BTFF4pKx7BM
The video is a little shaky, but the gameplay is quite good. aurllcooljay, who is a member here, figured out how to get into Doge's Palace by manipulating the air tackle game mechanic to give you extra range on jumping. Basically, you start to air tackle someone, but then grasp a surface along the way. He calls this the superjump (starts around 0:25). He then proceeds to kill everyone inside the palace while super/hyperblended.
The superjump makes for 3 non-story methods for reaching the interior of the palace. Here are the others:
http://www.youtube.com/watch?v=5DnoMn0Efnw
http://www.youtube.com/watch?v=vTLz0och4Pw
There are 4 methods if you count airwalk, which has been patched over.
http://www.thehiddenblade.com/airwalk-assassinate
Wow, that's awesome.
I tried this myself today and I felt invincible.
Also, there's this glitch where if you hit a Borgia courier/pickpocket with a throwing knife, you get the money, but they don't die.
Long distance harvesting rofl.
It took me a couple of tries and I did it! 
You feel like such an amazing person once you accomplish this feat!
That was very impressive! I'd be interested to know how many hours it took to plan and how many tries it took to complete.
Good question. I took a few hours at least, but I didn't keep track of the time. At first I couldn't get into the palace because I took a different route that didn't really work (I kept falling off a ledge I jumped on). When I got in there it probably took several tries to find the right travel path to get all the guards the quickest way (since some of the guards don't even appear until you are close to them). And as you can see the video wasn't made in one recording because I kept messing up by falling or missing a guard or two. But it was fun to do. Stabguy recently made a video showing different ways to get in the palace, and on youtube I made a video that shows glitches and expliots that can be done in there.