Chat (Enter) - If the chatbar is set to always be open, focus will be given to the chat text box so you can start typing. If the user has it set in their Preferences that chat will close on enter/return, then the chatbar will open if it is closed or close if it is open.
Start Gesture (/) - Begins a gesture by putting "/" in the chat text box. Gestures can be edited or created via the Gesture Window. Also, IRC-like actions can be used, i.e. "/me says hello" prints out as "Oz Spade says hello".
Always Run (Ctrl-R) - Toggles your avatar from running to walk or vice versa. Running while attempting to go up stairs or on uneven ground can sometimes cause your avatar to "shoot off" in a direction. If this happens you can press the space bar on your keyboard to stop all avatar motion (except for downward falling which is just slowed and also only works if you are not in chat mode).
Fly (Home) - Toggles your avatar from flying to not flying. Depending on your preferences, holding E or Page Up keys may also cause you to fly (this can be turned off in Preferences > Input & Camera). Also, if not in chat mode the F key will also cause your avatar to fly. Again, pressing the space bar can slow your fall and stop flying motions.
Create Landmark Here - Will create a landmark in the inventory for the location you are currently standing on, but this only works if the land you are on allows others to save landmarks to it. The landmark window will immediately pop up on your screen showing you that it has saved (if you wish to just save it for later and not use it, just click the X) and when you next open the inventory, the landmark folder will be expanded with the newest landmark at the top.
Set Home to Here - Will set your home location to the land you are standing on. Only works if the land is owned by you, a group you belong to, or at a mainlandinfohub. Once set, you can see where your home is by an icon on the world map and also teleport to it at any time. If you are killed in a damage-enabled sim you will be sent to your home location. Depending on your preferences you may also be logged in on your home land (Preferences > General). The default home location is set to the Welcome Area.
Teleport Home (Ctrl-Shift-H) - Teleports the user to their home location.
Set Away - Sets you to be "away". Your avatar will become hunched over as if sleeping while standing (if you don't use an animation overrider), and "(Away)" will be added to your nametag. Once there is activity in the SL window, your avatar will no longer be away.
Set Busy - Puts you into "Busy mode". "(Busy)" will be put at the end of your nametag, chat and instant messages are hidden, instant messages will get a "busy" reply (which can be set in Preferences > IM), and all teleport and inventory offers will be automatically declined. In this mode, you can move around the world and interact with the interface without it turning off busy mode. Clicking the "Set Not Busy" button that appears at the bottom of the screen, or clicking the menu option again, will exit out of busy mode.
My Land... - Opens My Land Window that shows all your land in Second Life, allowing you to teleport to it or show it on the world map. Also shows you the amount of land you have contributed to groups you are in.
About Land... - Opens the About Land Window, this window allows you to edit the preferences for the land you are currently on if you are the owner of the land. If you aren't the owner you can still view many of the preferences, which is useful for telling what you can and can not do on that land.
Buy Land... - If the land you are standing on is set to be purchased by other residents (or you specifically) you can click this menu option and the Buy Land Window will be opened. From the buy land window you can see more information on the land and purchase it directly.
Region/Estate... - Opens the Estate Window from which you can edit the preferences of the region/estate. If you do not have the proper credentials to edit the estate, you can still see the available options.
Force Sun - Opens up a submenu with several options that allow you to position the sun client-side (the changes will only affect you; no one else will see them).
Sunrise - Puts the sun at the sunrise position.
Noon (Ctrl-Shift-Y) - Sets the position to noon, directly above the world. This is the brightest time of day in SL.
Sunset (Ctrl-Shift-N) - The sun will be put to the sunset position.
Midnight - The sun is positioned to its lowest coordinates and the moon is visible. This is the darkest time setting in SL.
Revert to Region Default - If you have set the sun to one of the above positions, this option will revert the sun to whatever position the region you are in has it set at. So for example if the region/sim/estate you are in has the sun set to midnight, but you set the sun to noon so you can see better, then if you leave that sim and want to have the sun go back to "normal", you can click this option and it will reset the sun position to that of the sim you are then in.