The two towns, Zihuatanejo and Ixtapa, are so close together that you only need to take a local bus for 7 pesos and 15 minutes later you're in the other town. The buses are frequent, well marked and easy to get on and off. In Zihuatanejo, the main embarkation point where Jose Morelos and Benito Juarez meet. Several buses may be waiting for passengers at any one time, but get on to the first in line as it will be the next to depart. In Ixtapa, there are marked bus stops every couple of blocks along the main drag, but certainly across from the shopping center you'll find a waiting area for the return trip.
There are three bus stations in Zihuatanejo sitting side by side along the highway. The Elite / Futura station is the largest, with Estrella Oro in the middle and finally the independents in an office closest to town but not much larger than a convenience store. Having not particularly enjoyed my experience with Elite, I also wanted to arrive at the Estrella Oro bus station in Acapulco since it would be nearer to my hotel. Estrella Oro has hourly buses from Zihuatanejo to Acapulco.
Most of the buses are economy (100 pesos in 2008) but some are first class (119 pesos in 2008). The four and half hour ride included three stops where food sellers (and at one stop a beggar) came on board to pedal their wares. Other than that the ride was uneventful, but for some reason the bus driver didn’t play any movies.
the buses will get you around town for about 55 cents. from the main bus station, you can get to other cities by simply looking at the kiosks that sell the tickets and reading the destinations. you can ask for the price or it will be listed. buses are not actually going to each destination listed. i saw one destination listed, and when i went to buy a ticket, the lady at the counter said, no bus goes there. it´s just still listed on the wall. so you have to ask.
an overnight bus to puerto escondido cost us about $50 per person. we didn´t get on the bus direct because the tickets were all sold out. instead, we had to go to acapulco first, then continue on another bus to puerto. read about some dangers in the warning tip for this page.