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.
scarp scrap scrip scrape scroop scrapie scrappy
carp scarp carpi crap crop scrap scrip
scar scarry scary scare scarey scoriae escar sacra scaur score screwy scree scoria scry scurry sucre screw escrow