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