The first tool I decided to check out was Remember the Milk. Though I do think it was neat tool, I think I am more of a traditional, write on a scrap paper or in my planner type of list maker. To me, having to login and access my lists is more work than I am looking for, even if I can just access it on my phone.
The next tool I explored was Google Calender. I chose this one because I see it on sites all over and I've always been curious about it. I think it will be useful in remembering events and such, but similar to my tendencies with list making, I think I like my planner more than an online source. I have a feeling that I would fill my Google Calender with things, and then forget I did it, thereby accidently missing them. I am going to give it some time, however, and see if I enjoy using it.
There are other tools I want to explore, such as the ones to help remember passwords, and I plan to explore them in future when I have a spare moment.