Speaking anecdotally, it's been my experience that logicians have the best senses of humor, metaphysicians tend to a little pomposity and lot of wine, philosophy-of-language types are a little oversensitive to rules, and ethics students have the most fun. Though not a psychological disposition per se, philosophy of mind appears to require long hair - either huge beards or unkempt manes.
The question's a bit of fun on my part, but I hope ultimately pragmatic: Have there been any published attempts to relate personality types to fields of study in philosophy? Better yet, are there any robust attempts to recommend a discipline based on some kind of psychological profile? All this is to really ask - is there a way to judge, prior to study and determining one's interests a posteriori "which field of philosophy is best for me?"