Graphic block is my own way of saying writer's block except it applies to graphic designers.  Have you ever had a time where you didn't know what to add to your site or need new ideas? I'm sure most of use have been there at one point.

Getting Ideas
You're probably wondering "If I'm out of ideas, how am I going to come up with one?" The answer is you will not, eventually you will. What I suggest you do is take some time to visit your affies and if possible your affies' affies. What visiting other sites do is they give you ideas. The point of this is not to copy what they have, but to use their idea and add your own ideas to it. While browsing other sites you may subconsciously have an idea creep into you head. This happens to me very often. I will be browsing a site and suddenly I'll get an idea that may or may not be related to the site and I start building off of that then 10 minutes later, I have 5 different new ideas. It's exactly like the domino effect.

My brain doesn't work like that though. I'm not all that creative.
Since all humans aren't the same there are of course more than one way to get a new idea into your head. Since visiting sites didn't work you could maybe look around your room or your house and see what you can make and distribute. If you see stationary lying somewhere, you could maybe start offering stationeries. If you see your cell phone you could offer cell phone backgrounds. It's still the domino effect because one thing is caused by another, but this does not depend on an idea randomly coming to you. You take existing objects and you build off of it.

Your ideas don't work....
Ok, maybe building ideas off of things isn't for you then.  You can maybe sleep it off and you'll come up with something tomorrow or you can try do something else like watch TV. If you're too focused on one thing eventually you'll loose focus on it. For example, if you say the same word over and over again after about the hundredth time you will either forget what word you were saying or you'll get bored of saying it. This same principal applies to when you're overtaking graphics. So the last and final solution is to just take a break. You've probably done a lot already and your brain just doesn't feel like working anymore. Get away from the computer and the next time you get back on you should get new ideas ^_^

It's the next day and still no idea..
The break didn't help? Usually that's the key to solving writer's block, but maybe graphic block is slightly different? Another thing you can do is ask someone for their opinion.
You can ask them what they would like to see on your site or what they're favorite type of graphic is. If their favorite graphic isn't on your site you can start adding it.  You can also ask your affies or friends to help you by suggesting ideas. I'm sure after asking a few people you'll have a new idea in no time!