Unsure if this is posted on here yet but I thought I'd share something one of our priests posted on the guild forums. If it is posted I apologize didn't see one on my search.
You can use the nearest Lightwell without having to actually click on it and also without (permanently) losing your target by performing three separate actions in sequence:
/tar Lightwell
Interact with target
Target last target
To do these three actions with one bind you will need a keyboard with macro functionality or software like AutoHotkey.
Code:
+k::
Send [
Sleep, 25
Send `;
Sleep, 25
Send `'
return
+k:: means to execute the following commands every time shift+k is pressed (+ for shift)
Send [ causes the left bracket key to be pressed (/tar Lightwell macro, bound to [ with button bar mod)
Send `; causes the semicolon key to be pressed (Interact with target WoW keybind, cannot be used in a macro)
Send `' causes the apostrophe key to be pressed (Target last target WoW keybind or /targetlasttarget macro)
Sleep, 25 causes a 25 millisecond delay: these may not be needed but I put them in just in case
Both the semicolon and apostrophe symbols are part of AutoHotkey scripting syntax so a Grave accent character is required to make these characters literal.
I have one of the three thumb buttons on my mouse bound to the k key using the Logitech software so I just hold down shift and press it to use the nearest Lightwell.
Of course you can change any or all of these 4 keys to something else if you modify the script.
If you run with UAC enabled in Windows Vista or 7 you will need to run the script as Administrator in order for it to work within WoW.