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.
scare scarey scar score sucre screw scaur scary scree square screwy scarry sowcar soucar secure scoriae scry scour sugar cigar saker sacra saggar scurry sacker sucker squire scoria sagger soaker sicker seggar sugary cicoree saggier saguaro suckier
scare care decare daycare car square soucar screw score scary ocrea acre fiacre lucre core quaere acari eagre decree chickaree cure scree quare nacre meagre puggaree scarey vicar scaur picara picaro crew carr secure sowcar sucre pugaree scar dekare shikaree