Profile Name: Office Profile
Description: I use this profile so that when I arrive at work, the phone knows it (by using cell towers) and a) lowers my screen brightness by half, b) places the phone in Silent Mode, and c) switches WiFi off. a) and c) help with the battery life, and b) keeps any noisy calls from coming through and disturbing the rest of the cube monkeys.
Steps:
1) Tap the "+" to create a new Context (i.e., a condition that will determine whether or not the profile is active), and choose the "State" option
2) On the next screen, choose the "Phone" State Category
3) On the next screen, choose the "Cell Near" Phone State. (NOTE: You'll have to be at your office [or pretty close] when specifying the "Cell Near" state, since Tasker will determine your cell tower location there. And of course you can't be in Airplane mode or anything like that...)
4) On the next screen, tap the "Scan" button to determine your cell tower location. Once the text area is populated with the location (e.g., GSM:12345.456789457 / 8 <), tap the "Stop" button.
5) Tap the back arrow at the top left of the screen to go back a screen. (To the right of the arrow will be the words "State Edit" with "Cell Near" underneath it.)
6) On this next screen, a dialog box will be open to create a new task ("Enter Task" window title). Choose the "+" next to "New Task". When prompted, enter a name for the task (e.g., "Work Arrive") and tap the checkbox next to the text area.
7) The screen that shows next is the "Task Edit" screen. Tap the "+" to create a new Action for the task.
8) On the next screen, choose the "Audio" Action Category.
9) On the next screen, choose the "Silent Mode" Audio Action.
10) On the next screen, tap the "Off" option under the "Mode" header to see all options available, and tap the "On" option.
11) Tap the back arrow at the top left of the screen to go back to the "Task Edit" screen. The "Silent Mode" action should be displayed.
12) Repeat steps 7 & 8 and choose the "Display" Action Category.
13) On the next screen, choose the "Display Brightness" Display Action.
14) On the next screen, slide the "Level" meter to whatever brightness level you desire (the lower the number, the dimmer the display).
15) Tap the back arrow at the top left of the screen to go back to the "Task Edit" screen. The "Display Brightness" action should be displayed.
16) Repeat steps 7 & 8 and choose the "Net" Action Category.
17) On the next screen, choose the "Net" Action.
18) On the next screen, the "Off" option under the "Set" header should be selected.
19) Tap the back arrow at the top left of the screen to go back to the "Task Edit" screen. The "WiFi" action should be displayed.
20) Tap the back arrow at the top left of the screen to go back to the Tasker Profiles display. The profile should be listed with a crazy-long name like "Cell Near ..." and directly underneath it the same name with a right arrow and the name of the task just added ("Work Arrive").
21) Tap and hold your finger on the duplicate name underneath to pull up the menu to "Add", "Delete", or "Name" the item. Choose "Name" and type in a name (e.g., "Work Mode") and tap the checkbox. Both the header profile and the "Context" item underneath will have the same name. (To rename the profile to something different, tap and hold the profile name, and tap the "A" at the top of the screen. Enter a desired name and tap the checkbox to save it.)
ALMOST DONE...

Now that the profile knows what to do when you arrive at work, now it needs to be told what to do when you leave...
22) Tap the profile name to expand it (if not already), and tap and hold your finger on the "Work Arrive" task.
23) On the dialog box that appears, choose "Add Exit Task", and then the option for "New Task". Enter a desired name for the task (e.g., "Work Depart") and tap the checkbox.
24) Refer to steps 7 through 19 to add almost-identical tasks as those created in those steps, except this time you will choose the opposite values for the settings (i.e., for the Wifi task, you'll choose "On"; for the Silent Mode task, you'll choose "Off"; for the Display Brightness task, you'll choose a large number to increase brightness). Use the back arrow to get back to the main Profiles screen, make sure the Off/On toggle next to the Profile Name is set to "On", and that's it - Tasker will auto-adjust the settings specified as you arrive at, and leave, your office!