Formerly a long walk through the jungle, the border crossing to Puerto Barrios in Guatemala is now quick and painless. Just about every bus heading west on the highway from Omoa [1] is going to the border, charging US$2 for the hour-long ride. Take a taximoto from Omoa to the highway and flag down the next bus you see. There is no charge to exit Honduras [2], but there’s a US$3 fee upon entry (or re-entry).
Links:
[1] http://www.moon.com/destinations/honduras/the-north-coast/puerto-cortes/omoa
[2] http://www.moon.com/destinations/honduras