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.
greeter greater greedier grater garter grouter gritter grittier garotter garroter groutier grottier crater krater carter grader curter critter quarter guarder creator grodier gridder courter courtier criteria cowriter quartier carrotier carder corder cruder crittur crowder curator curdier
greeter retear breeder ferreter fretter greater perter treater ureter
greet great greed greedy agreed egret