You need to know the address. Detroit has pockets of good and bad blocks. A house on vaughan around Joy is a bad area with a lot of board ups and burn downs, but if you go around 6 mile it can turn into nice 3 bedroom brick bungalows. I have some nice investment properties if you are interested. You can email me email@example.com.
Graham, "decent" is very subjective. There are number of websites that some of our Trulia investors can refer you to so you may decide for yourself. Renting out a home is one concern an investor will have with any city. Another concern should be the cities cooperation with landlords and investors and the ease with which they can conduct business within any cities limits. If you do not have a Realtor or a property manager, I would strongly suggest that you contact a few to help you.