Victoria Island
Return scrolls (town specific) are your best bets. they only cost 400~600 mesos and are cheaper than taking the cab and saves time when traveling on foot. after all, time is money. If you have a magic seed, you can travel between Ellinia and Leafre.
Ossyria, Ludibrium, Aquarium
Best continents ever. if you're a high enough level (or if you have dark sight/haste/teleport/etc), you can travel on foot and it'll be faster than boat rides. You can travel between orbis, el nath, aqua road, herb town, korean folk town, omega sector, and mu lung.
Leafre, Ariant, Magatia
sucks. you WILL need a boat ride for this at some point. Manji can take you to ariant if you finished his quest, but he limits you to 5 times. and you'll need a magic seed to get from leafre to ellinia.