The command /visit allows you to quickly and easily visit another player.
To set your visit location simply type /visit set when in a valid location (these can be anywhere valid in any of the worlds). A valid location is anywhere with a solid 3x3 block floor and where the 3x3x3 blocks above are completely empty.
To visit someone else's visit location simply type /visit [NAME] replacing [NAME] with the name of the player's land you want to visit. It's extremely easy, if you're not a VIP simply wait 5 seconds and if the location you're trying to visit is still valid then it will teleport you to the location set as above. If you are a VIP then the teleport will be instant.
To clear your visit location simply type /visit clear. This will remove your current set location. You can always simply overwrite the original one if you want to though with /visit set.
To check where your current visit location is set to simply use /visit check, this will give you the coordinates of your current visit location as well as informing you if the location has become invalid for whatever reason.