I do a lot of development split between two machines, a large desktop machine (iMac) and a portable laptop (Macbook Air), both of which have locally stored MySQL databases. Often I'll run into a situation where I have two out-of-sync databases across the two and I need to access one or the other to replicate changes.
I curse my lack of preparedness: "I should've set up that Dynamic DNS account last time I encountered the problem". But wait doesn't Back to My Mac do exactly what I want, easily and for free? Yes, yes it does.