Ian, the first thing I would say is you have some great advice there!

In my experience your boss is key to your promotion. I'll assume you are not trying to take his job and will be looking to be promoted to some other role. It will be your boss that will decide who to promote or at the least who to put forward! I'd recommend a couple of things here, firstly as recommended above talk to him about where you want to go - you won't get it unless you ask. Second you have been there three years so must have built up some knowledge (other than how to best trick Dave from accounting) try and share that with co-workers - it's hard to get promoted if you are ireplaceable!

If it's possible try and take on some of the responsibility of the role you are aiming for - if it is anything like my place you have to almost be doing the job before they give it to you!

Good luck!