If you want to get some tips on comedy writing and see what your peers are up to, you might want to have a look at the BBC's "Comedy Soup" website. The idea is that aspiring comedy writers can create a virtual portfolio online and maybe their efforts will be spotted by agents, producers, or other fans.
Comedy Soup editor Vicky Dolan writes, "In addition to the simple entertainment value, the site offers advice and tips for those who want to get into comedy and BBC material that people can make use of."
The site welcomes videos, audios, and images (like cartoons or satirical photos). But before submitting anything, check the conditions--you're giving the BBC the non-exclusive right to do pretty much whatever it wants with your material. Additionally, Gail Renard, member of the Board of the Author's Licensing & Collecting Society warns, "my main concern is that the material on there can be plagiarized by less scrupulous users."