Not quite sure what you mean by prop creep, are you refering to prop walk where when you go astern, the stern kicks out to one side, and as soon as you go ahead, it kicks to the other?
If so, a lot of people make use of this to manoeuvre the boat as she will turn onw way much better than the other. However, if you want to reduce the impact of this (and also improve sailing speeds) swap your existing fixed blade propellor for a folder like autoprop or gori, as these are supposed to improve things.
If you do mean prop walk, it is most prevalent at slow speeds astern when the propellor is "pulling" and the rudder has little influence as there is no water flowing over it until the boat picks up speed. It is less noticable when going forward when the propellor is "pushing" and it can be countered by the rudder sooner because of the prop forcing water over the rudder (prop wash) before boat speed picks up through the water.
If you have a 3 bladed prop, you can reduce initial prop walk slightly by going to a 2 bladed prop, but the 3 blade accelerates faster and the effect goes sooner - the situation is different rather than improved.
The effect does reduce as speed increases. Whatever you do you won't get rid of it completely (short of putting in twin screws). Once you are familiar on how it affects your boat it can be a useful feature for manoeuvring in close confines - my boat pulls to starboard in reverse and makes coming alongside to starboard a lot easier if used correctly, but I have to make allowance for it when leaving. This article describes it quite well.
The only effect a bow thruster will have on prop walk is to move the entire boat sideways as opposed to countering a turning motion and would not be a solution.
Pardon me for hijacking your thread, but this may be relevant. Lots of commercial vessels such as tugs, rig-boats, workboats and fishing vessels have nozzles fitted round the propellors. This is to improve thrust for a given power output, but methinks a side effect would be the removal of the propwalk effect. Personally I use propwalk to assist manoevring but wonder what other forumites think upon the subject. Shall now duck down and await a blast of informed comment! /forums/images/graemlins/grin.gif
Going astern put the boat in reverse gear (with the rudder amidships) open the throttle fully (as many rev's as pos). Once you are moving astern take it out of gear, you should have enough momentum to stear and you will not have to counteract the prop walk. Has worked for me on many occasions in tight situations. I suppose going forward is the reverse but find it is only going astern that I have problems controlling the boat. Also long keel.
Personnally, I dont think you want to over come it. Better to understand, nuture and live with it. It adds to your manouvrability - it can be used to shorten your turning circle (to port) and to come along side a starboard tie smartly.
True, getting off from a starboard tie needs some planning, but its nothing that cant be sorted with warps and a bit of power.