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.
woopses whipsaws
copses woopses tapises eposes upases deposes spouses reposes popsies papooses opposes lipases lapses lapises gypsies gipsies apses supposes apposes pases puses posses posies poses poises lupuses opuses pappooses reopposes sepses biopsies
woops wops whoopees whoopies whoops whops swoops swops