Ok, a LOT of people have had trouble formatting meme entires. Ok, here's the guide to doing it, for people that won't click the not-so-hidden KYM provided link.
To italic text, put underscores around the desired text.
To bold text, put asterisks around the desired text.
To change the appearance of links, you put what you want to name your link in quotation marks, then place a solon right after it, followed by the link, no spaces.
For bullets, put an asterisk at the left side.
For images, put exclamation marks around an image url.
For videos, use the embed codes at the video page.
For headers, put h1. at the left for HUGE ones, h2. for moderate size ones, and h3. for small ones. Be sure to press enter twice after.
For numbered lists, put # at the left.
To use typewriter style font
, put @ around the desired text.
For strikeout, put hyphens around the desired text.
To align to the center, use p=. at the left.
For everything else, here's the textile format guide.