I have a blade sharpener, and I tell you what it works like a charm. I used to milk my blade for all it was worth letting it go dull and using it for much longer than I should, but once I purchased that sharpener a twist or three and it's good to go all over again. It's well worth the money.
Oh and I only buy the Olfa blades, my current was has been sharpened three times and is still cutting beautifully. (a single replacement blade runs $7.49 Joann's reg. price)