Productivity Tools

I enjoyed looking at the productivity tools. I can see a purpose for all of them, but it is going to take me awhile to get used to some of these online tools. I think part of it is because I am a user of only portable computers, so I always have everything with me. If I had a desktop I think I might look at them differently. Here is a quick review:
Bubbl.US--I like the look of this and I like concept maps. But I don't think I would use it because I already use Inspiration.
Zoho Show--The link did not work. I looked it up and it is:
http://show.zoho.com
This site does presentations online. Again, pretty kewl site, but I can do more in PowerPoint and Keynote.
Remember the Milk--This site deals with tasks and has an iPhone app, but I do not use the task feature, so not really interested.
30 Boxes--This is a nice online calendar. But again, I already have one and can use it online at MobileMe, so not interested.
LibraryThing--I liked this a lot. A nice opportunity to hear others impressions of books.
TrailFire--Probably the lease interesting to me.
Knowtes--I liked this a lot. If it would not be blocked in schools, I think this would be a great student tool for flash cards.