yep ... that would work too if patso wanted to go for an adventure ... and since s/he is thinking of going fixed, we can assume that is an option.
and you bring up a good point to consider: while most frames that are ripe for conversion are older, they tend to be found sporting 27inchers while most newer wheels are 700s. is it just as easy to get a new wheel set for a fixie built up with 27s? i realize the only time it actually matters - unless you are trying to recycle some rims, as moxfyre suggests - is if you are worried about brake reach but the question remains ... particularly because anyone new to fixed gear should run at least one brake at the begining.