Found this on GigaOm .... he says 'This is one article everyone should read', so here you go!

Outcomes vs. Activity

Why everything a founder does must be a means to a specific end

I tap myself on the head every morning and ask that question...from my experience though the really challenging question is "Will this outcome matter tomorrow".. I think clear outcome prioritisation is an essential addendum.. especially if you have tight resources.

I found that I've personally wasted heaps of effort on things that at the time seemed 'outcome driven' but by completion don't matter anymore because

1. the goal posts have moved
2. The outcome wasn't as important as I originally thought
3. Future outcomes render the present one redundant, so the effort is wasted

 I can't see any solution to this other then trial and error- but I think if you're aware of it you're more likely to learn from the errors

A little mental arithmetic I've found helps me- what's the cost of doing X vs doing nothing or something else, and what is my expected return, and how likely is it that I'll achieve that return... (sometimes this can be very depressing)

some great articles on that site... not going to be a very productive morning for me I think