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.
soldiery soldier solder solider solitary solidary slider siltier saltier slatier slitter sledder sluttier sleetier slittier solitaire salter slater sultry saltire saluter slotter salutary zoolater zoolatry
soldiery leadier bladdery bloodier bouldery cloddier cloudier gladier moldier mouldier soldier wieldier
soldi sold soldo soled solid solidi