I once posted a thread about a local church with rather unique architecture that was up for sale and asked who but another church would be interested in re-using it (epilogue: another church bought it). Since that time I have encountered numerous examples of how churches (many of which had distinctive architecture) have been re-used in very clever and innovative ways.
Churches are but one example of distinctive buildings/land uses. My question for you is what types of buildings/uses tend to be worst suited for re-use due to appearance, function, renovation cost or other factors (that, or stick out like a sore thumb when they are re-used)?
See the responses here.