It's possible to use built in keywords in order to mark some lines in you code for later reference. For example, I use the "TODO" keyword as a remark over a set of lines I know I'll have to change later on -

As you can see, my TODO task is now appearing at my Visual Studio .Net "Task list" which is great for a constant reminder.
As default, the Task list shows only the "Build Errors" so in order to support other keywords you'll have to (mouse)right-click over one of the table headers ("Description" for example) -> Show Tasks -> All (or any other suitable option). In addition, you can select how to sort the results by (I use "Priority").

* If you want to change the custom tasks priority or names - go into Tools-> Options... -> Environment -> Task List.