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.
seism sesame cesium zoecium zooecium
deism seism ism besom gismo jism miasm disme chiasm
seis seise seises sis seize sissies sews seizes seas sees seesaw psis eses peises reissues seesaws sissy oses sisses sues uses