I am a Server admin and i Want a Cape plugin really mutch. It would be cool if you could make tha cape in-game but only players that are op can do it. If anyone could make this plugin i would be very thankful If anyone can make this plugin let me know
... Two people just gave you the answer: Spout. And creating images in-game is impossible (unless someone creates some sort of Spout GUI that can). The bottom line: Spout.
You need Spoutcraft and a cape plugin from Spout's website. And please tell me you don't mean MAKING a cape In-Game?
Want capes on multiplayer? Spout. FULL STOP *dont want to feed the fire but* there are some client side mods that can do this.
I like to use the term nailed. not screwed, it refers with a sense of "to screw" as a means of "exerting pressure or coercion", probably in reference to instruments of torture.
There is a client mod called SMP Capes (by ZaphodX of PlanetMinecraft) that allows anyone having the mod to see capes. Once you have installed the mod, upload a cape to her website and you will be able to see it in SSP and SMP. Other players with the mod installed can see the cape as well! However, it will allow everyone to have a cape, not just the OP/admin. I tell all the players on my server to install this mod so that they can enjoy capes, as I would rather not force Spout on people. Just so you know, it is only a single modified .class file and works well with OptiFine/HDpatcher, Rei's Minimap, and other mods. Link below... http://www.planetminecraft.com/mod/smp-capes/
I would use spout instead of some client mod, then in the future if you wanted you could add custom blocks, or items, or guns, or a virus, or a server within a server, or vanilla, or Bukkit, or canary even!!! The possibilities are endless!
Those capes are implemented by Minecraft itself. You have two options if you want a cape. Some kind of client modification, or use the SpoutPlugin, and SpoutCraft.