Well, the best way to go faster is to improve your form rather than just knacker yourself. You could try Chi Running, it takes a little while to get used to but it really makes a difference straight off the bike. You use different muscles than normal style running, so those quads that you hammered up that hill cycling don't matter. That makes you faster because of less fatigue. Whilst it doesn't really matter over the shorter distances, it can make a huge difference over the longer ones.
There is a book and video, and I believe that there is a coach in London who does weekend intros.
For a faster and less exhausting swim look at Total Immersion.