SDL_oglblit is a library for doing fast, hardware accelerated 2D operations with SDL surfaces using OpenGL. It supports hardware rotation and scaling while blitting with no cost in regards to performance. The library does not do any inter-surface blitting operations, all such operations will have to be done using normal SDL blits before converting the surfaces to OpenGL textures, and should be avoided. SDL_oglblit is distributed under the GPLv3 license.
If you're using SDL_oglblit in one of your projects, drop me a line at noname@ this domain (you don't have to, but I like knowing if people find my libraries useful ;)