I know of few 0% installment loans outside of consumer finance ones (buying a new bed for example), which may not be what you're looking for. Dell financing may be an example of such, Apple isn't.
If we're just talking FICO purposes, my typical recommendation is to pay the 2% APR (4 year term, 3% for 5 year) at Alliant Credit Union for their $500 share secured loan... yuppie food stamp, total, over the 4 year loan /yawn. Have to deposit the money and leave it there, but it's the most effective method for doing so that that I've found, and to my knowledge is best in class compared to everyone else currently though that sort of thing changes over time.
