How to do my "To Do" list

Like many genealogists out there, I have a long list of genealogical "To Do" items that if I don't keep them somewhere, I forget them.  A list of them is a necessity.  But now that I have switched from PC to Mac, where should I create this list?

I used to be able to keep them in my Outlook Task List.  When I changed to Mac, the Microsoft Office package I purchased did not include Outlook.

This is a fresh start for the To Do List so what options do I need to fulfill?
*Do I want it to be portable?  If so, how do I want it to be portable?  -              Computer, iPhone, or old school paper?
*Inside of my Genealogy program or outside?
*Will it be related to a specific person or broader?

I would like to look at the last two questions first.  In the past, I have kept person specific lists in my genealogy program (Family Tree Maker for PC).  As I transitioned my files, those person specific to do list transferred over int o Family Tree Maker for Mac.  However, I have other genealogy To Dos that don't fit in.  So it would appear, I need some time of non-genealogy program list.

Now the question of portability comes into play.  I could do this the old fashion way and make a list on paper.  Very portable...but not very efficient.  Unless I plan to do them in the exact order they are listed, you end up with several pages of items with varying number of outstanding items.  Then you spent time condensing them into a new list.  As I said, not very efficient and a waste of valuable genealogy time in my opinion.  So I am definitely looking for an electronic method.

Currently, I do not have an easy method of inputting my extensive "To Do" lists on to my iPhone.  So until I find an app that I transfer between my computer and iPhone easily, I will stick with a computer version.  I am sure there is probably an app out there that would allow me to do this.  However, I am still trying to get a handle on the Mac World and am not sure I would choose the best product at this time.

My old standby for To Do lists has been Excel.  I can build a table of different types of items to be done and even keep notes on the status of the item.  I guess for the time being this is the solution I will peruse.  Unless someone has a better idea?