While ideas may not have any monetary value, I think they can still be a good source of inspiration. So for those of you that have game ideas, do you have a way of storing them, and if so, what does it look like? How many ideas do you currently have?

I keep my ideas stored in a folder on my hard drive. At first I had 2 or 3 of them, then I started studying game design and programming, and my game idea collection has grown quite a bit since then. I'm up to around 20 now. Here's a couple screenshots:

Those you tell you that ideas are worthless probably have bad(or none) ideas themselves.
My 5 cents on the topic.

Otherwise I've got 3-4 ideas for a copy games with some sort of a twist. I just keep them in my head(knowing that, my job has nothing to do with game design).

I keep them in a wiki for now but i think i will change to having a google drive directory for them. More easy to show a google doc to someone or to print it. Six ideas that have enough written on them so it is possible to start to judge them :).

I do this as well. Ever since I was very young I was told it was a good practice to write down ideas, but I ignored it...

Then when I was in my teen years I saw "Jackie Chan My Stunts" and learned that he kept all of the ideas he has and reference to it. Even in his wallet. After that I started always writing them down.

See here:

When I was school-aged, I kept it all in notebooks -- never a single, designated notebook, mind you -- just whatever notebook I had on me for class when inspiration (or boredom from class) struck me. I kept, and moved with me through several apartments a large box stuffed with these notebooks that contained game designs, drawings, or other things. Finally I took an afternoon to go through them all and carefully ripped out anything I deemed worth saving. Those are still in a box, albeit a much smaller one. Probably one day I'll digitize them somehow.

When I became older I started recording more of these things digitally.

• I tried Wikis, which are fairly well-suited for these sorts of incremental thought exercises, but the trouble is that you have to administer the damn thing and also the markup language is usually a pain in the ass, along with the built-in entry editor. Probably there's a Wiki package out there that solves those pains, but I never found it when I was going through the wiki phase.
• Microsoft OneNote is pretty good if you have access to it. Its like a wiki, but more WYSIWYG and it has some nice features like full-text search that extends even to being able to OCR text (even handwriting) in images. Alas, its not entirely cross-platform, and its also difficult to track under version control. You maybe don't need that, but its part of the workflow I use for keeping all my important documents safe, and its always nice to be able to find that information you deleted because you didn't think it was important any more.
• Right now my preference is for Emacs Org-mode -- its kind of a text-based One-Note, it allows you to outline documents hierarchically, create multi-level bullet-lists, track progress, and link to other documents and contacts straight from the keyboard. Since its text-based it plays nice with version control, and emacs runs everywhere. You can publish Org mode files as static HTML pages using Jekyll, which is what powers GitHub-Pages, so I can easily share and publish the designs colaboratively with just a github account.

I use folders and folders and folders of general design notes (>24k files, 1,400 folders), and some folders of more project-specific thoughts.

My only regret is a lack of a good (general) tagging system in Windows Explorer, so I often have to copy the same file to multiple locations to categorize it properly.

One of these days I'll write my own file-browser with tagging support that I'd run alongside Windows Explorer just for my design folders.

I put my ideas on whatever inside Essential PIM. I bought life license back in 2007 or something. Best purchase.

My ideas are separated as several notebooks , few folders, some whiteboards. But hope to organize them soon by getting a Surface like laptop (Pity Microsoft Surface isn't available worldwide but a decent tablet/laptop like Samsung TabPro S or Acer Switch 12 Alpha with 1440p 3:2 IPS screen and pen will solve most of my issues.)

My ideas are separated as several notebooks , few folders, some whiteboards. But hope to organize them soon by getting a Surface like laptop (Pity Microsoft Surface isn't available worldwide but a decent tablet/laptop like Samsung TabPro S or Acer Switch 12 Alpha with 1440p 3:2 IPS screen and pen will solve most of my issues.)

Now I remember. While I mostly at my PC (hence, Essential PIM) OneNote is easy to use on Surface. With typing and drawing using surface pen.

but i mostly use EPIM for game ideas, as I mostly play games on the PC.