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.
crocs crocus crocks cariocas cricks cracks crucks croaks crooks cargos carcass croquis carcase cargoes caracks carracks curacaos curacoas groks grogs crags corks carks crakes creaks creeks gregos karaokes crux
rocs tarocs durocs crocs frocks mercs arcus darics seracs circus progs orcs trocks torcs barcas groks recs rocks arcs brocks narcs lyrics cercus heroics marcs taroks sargos sorgos frogs pargos orcas largos torics narcos grogs crocus crocks cariocas cargos trogs
croc crock crack cracky crick crickey croak croaky crook cruck scroggy