Is it acceptable to say how you are
learning a new technology (eg C# 4.0)
as one of your tasks, alongside the
actual deliverables?
Learning time is legitimate, and if the company sees it that way you can make it a task.
Full disclosure: although the company I work for sees learning as a part of the process of software development, I don't actually put individual learning tasks into my weekly reports; I just build it in as a part of the larger development task.
My task is constant everyday so it is
embarassing to say how I am doing the
same thing (which is not a fun task -
more admin type) while the other team
members are doing C#/ASP.NET - the fun
stuff. This obviously dents my morale
Where I work the people that have ongoing "areas of achievement" list the individual tasks they achieved when we meet each week. Some of these tasks can be quite mundane, such as "I went to this meeting," or "I ran this script that took 2 hours," or even, "I read this chapter of that book because I needed to know how to do this." Our company understands that this is the nature of the work. You shouldn't be embarrassed about this.
Full disclosure: I break my "areas of achievement" into smaller goals that can be completed in roughly a week's time, so that each week I can say that I completed something.