You have to clarify what you mean. Yes we have simple server "mods" that do stuff like Permissions, Commands and some cool movement ... also NPCs ... tease tease. But nothing serious that adds loads of new blocks and mechanics.
I'm renting a root server out in Germany. On that I set up this Minecraft server. This gives me full control over everything. So it probably isn't the kind of "renting" you mean.
No, you can go everywhere you like and do anything you like ... except trash other peoples creations. Though we have Factions to hinder you do that.
Ye ... but somehow he disapeared. But if you know Kane ... he will come back eventually ^^
On a side note:
Made the Sign algorithm also correctly display non converted, pre 1.8, Signs ...