I started keeping text files of ideas a year or two ago, but the system quickly collapsed due to its own complexity.

I am a journalist and a blogger, and so I started out with three files. -- blog ideas and article ideas. I also had a file called "inbox" for random thoughts, most of which would get turned into GTD next actions.

The first difficulty I encountered was that it wasn't always clear, up front, what's going to turn out to be a blog, and what will be an article. Back then, I went by gut feeling, now I think I have some good thumb rules -- but either way, this decision should not be made at this stage of the process.

Then I said to myself, "I really ought to group similar ideas together, because they're likely to all end up in the same article or blog." For instance, I'm a Second Life enthusiast, and I'm working up a list-type blog post or article: "N Easy Things Second Life Can Do To Make Itself More Useful And Attractive" So I really ought to group all those ideas into a separate file.

So I started keeping separate files for separate projects. Separate ideas for separate contexts, too -- for example, I'm one of those people who gets only limited time with his boss, so I had a whole list with the filename, "@Tom."

Quickly, I had a half-dozen lists, then a dozen, and eventually the whole thing got too hairy and I had to give it up.

But then I heard Merlin's talk at Macworld, and he mentioned, in passing, while making another point, an "ideas" file. And I thought to myself, "One file for EVERY idea. That's the ticket!" Just open Quicksilver whenever I have an idea for something, invoke the append-to command, append the idea to the "ideas" file, and then move on. Read through the file and organize occasionally. Very much in the spirit of the "trusted system" in GTD.

Only now I've opened a second file -- I've started a Facebook group for InformationWeek (the publication I work for), and I'm using the "Post" command to post links to selected articles. I like to do that once a day. When I see an article during the day that should be promoted, I append it to the "promo" group, and I plan to check that group every morning.

I put next actions in OmniFocus. It's usually pretty easy right upfront to tell what's an "idea" and what's a "next action." Or it seems that way to me.