I've taken a list of English words, and examined each of them to see what they sound like (using the PHP metaphone function). This page lists the most common metaphone codes, along with their words. You can also search for a word of your own, and see which words sound similar - and which ones rhyme, and which ones alliterate.
scroop scarp scrap scrip scrape scrapie scrappy cecropia
scroop crop croup grope group regroup
sacra scour sucre scurry scry screwy screw scree scoriae scar scoria score scary scarry scarey scare escrow