Well, I've joined a cult, well, kind of. I've been using GTD to help organise my life and my thinking for nearly six months now and I am amazed that it has lasted so long. More than that it doesn't seem a question of "using" anymore, more that's the way I do things. Basically, for me, it works and works well to complement the way I already organised myself.
Of course the system is under constant review and testing. Sites like 43folders offer ongoing ideas to add in and try. Some of the things I've done that I like are:
* Organising my Lotus Notes into GTD type categories and adding icons to quickly file mails into them. Notes isn't exactly the friendliest of email tools and it's hard to change much but the system works well for forcing me to deal with the massive amounts of mail I get at work and make sure that nothing slips by. Basically emails get read and then either deleted, replied to, archived or put into a Next Actions folder. I do have a waiting folder and a someday/maybe folder but they don't get used so much.
* Sharepoint site for my team. I have set up a to-do list for myself which I use to complement the email list. Everything work related should be in one or the other.
* Gmail. It shouldn't be as good as it is but it is. Emails are treated the same as at work. I've also set up filters to detect +... after my address so that I can use it as a kind of todo list for home as well as archiving writing, etc. I've also created entries in my address book for these filters so I just type in "todo" into the address bar to automatically save and file emails when using the Gmail to record stuff.
* Del.icio.us. Part of a general shift to keeping more stuff online. I use a "star" label to mark things out as something I want to look at later and added the feed for that tag into my rss reader. Or I could live bookmark it in Firefox.
Am still having a few problems integrating it into home life. It works well but I tend to find I'm not as focused outside the office. And I still haven't finished the book. It's good, but who has the time to read books on time management?