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.
slope slop slipe sloop slype saloop salpae sloppy salp slap slip salep salpa sleep sleepy slippy
elope slope lope lop wallop slype jalop loupe slop loup saloop lollopy kelpie galop culpae lipe loop flop slipe bloop salpae jalopy glop calliope lollop clepe plop clop gallop collop blype sloop dollop shallop