When the CH wants to view the work that you've done, he will want to see it full screen the way it would look like as a website. I recently found this site, http://www.codedpreview.com/, which allows you to upload and make it look like a real site. This better showcases the design that you have making a better influence on the CH. When you upload currently it tends to blur somewhat. Maybe that is better for fighting stealing, but people will still be able to easily copy what you have right now anyway. Just a suggestion, I've been currently using this website and it has been working well.

Add the ability to place comment "tags" on images directly (aka facebook photo tagging).

We want to be very interactive with designer during a contest, but it take a lot of time to describe sections of the creative/image that needs to be changed. We have to say "copy in upper right corner" or "the little image/graphic in the middle lower part that's blue" to try and get our point across.

That is very time consuming for us, but it's important to us and the designers that we give detailed (and constructive) feedback so we can iterate the designs quickly and effectively.

If we could simply place our mouse over the area we want to comment on, click to tag it, then type in our comments, it be so much faster for us and reduce the amount of confusion trying to communicate to designer.

This would be a HUGE help as a Contest Holder.

Is it so difficult to hire a few people who will be moving clip arts and copied drawings from the contest? Why other designer's must waste their time on the net finding the stolen logo or drawing? Of course, this option should be kept, but if you want to play fair with the fair designers than one should do that. I think most of designer's will agree with me that most of clip-arts are pretty recognizable. Some are just poor combination of stolen drawing and CH's name of the firm, others are parts of existing drawings just glued together. Sometimes I knew something is a clip art, but I'm not willing to search the whole net to find a original one. I recently entered a contest where two different designers entered the same lion design in to the contest.! I commented this in a comment place, but there were not reactions. Or, a few times I was trilled with winning designs, but so disappointed when I accidentally found they were stolen from somewhere. Does anyone checks at least winning designs? I know that next time I see such a case, I will not write too you, I will write to the original logo owner and let him decide if this is a copy or not. So, I am aware this is a cost to you, but if I doubt (know) something is a clip art, it would be nice that I have someone to go to and let him check that design.
There is more. Why in the earth you are giving a chance to cheating designers to remove their faulty work before you did it?! He must be banned from the contest immediately. If he is guilty, of course.
The thing is, dear 99 design staff, I can not agree with you that you are strict about clip arts. You let those things to other designers to worry. This is not professional of you. You should have a group of people who working on this. For example, I commented in two contests that they are full of clip arts, but nothing happened. I see other designers do the same thing often, but I have never seen moderators banned someone because they saw a clip art that isn't reported. I, of course, want to have an option to report a clip art, but this is not my job. This is your job, and you are not too eager in doing such work.
I really think this site is very good organized and I understand you just want to make money, but this is not professional of you. My next suggestion will be to organize a 99designer's union and than, in the future, you will must consider things like that! :)
Thank you for your attention and sorry for my poor English.

Currently a new CH cannot hold a blind contest which means they give far less submissions than expected. I know for a Blind Contest to work the CH has to be active and provide lots of detailed feedback which is why new CH's aren't allowed to use the feature at the moment.
However as a new CH, it's frustrating that I get several requests from designers to make the contest blind but I'm not getting any submissions. Instead of blocking new CH's they should post warning to any CH wanting to make a contest blind about the need to be active and give designers useful feedback. But if a CH doesn't post enough feedback to designers in their contests they can get banned from the blind contest feature until their record improves.

There should be some fairness with short listed designers as the wining price of a guaranteed design in case no winner has been chosen has been divided equally to all those designers who participate in it and also have one at least one contest according to 99designs.com, I appreciate this idea but please edit it as in my contest the award is $1120 CH chose 5 finalist and run the final stage more then a month and still not choose a winner. Now the amount will be distributed among all participates but we 05 peoples work harder then all other participants so please change this rule and distribute wining price among the finalist only if the CH run final stage more then three weeks. Thanks