I too am a big fan of LifeAgent as a network backup solution, both for Internet-based storage (which they provide) and a network-based backup drive (which I have in my office). The interface, however, is almost too sparing and minimalist and I also have problems figuring out where to view and change my settings, add a new backup schedule and so on.

The key is to know that the very latest Mac applications are moving in what I think is a bad direction, towards hiding all the additional functionality behind the "gear" pull-down menu on the window edge.

On Memeo's LifeAgent, the lower left corner of the app window looks like this:

You can see the "gear" I'm talking about: that's the key to the functionality you seek. Before you click it, though, make sure you've already highlighted the specific backup you want to work with, as I have done below:

You can see here that I have both a network drive backup, the first on the list, and an Internet-based backup to the Memeo drive. The former is almost done with its update, but the latter is going to take forever since I'm trying to upload 13GB of data. I'll change that as we go along...

Click on the "gear" icon now and you'll see the options we seek:

Choose "Change Backup Items" and you'll now see a list of all activated backups for this particular choice:

I don't need to back up my entire Documents folder - which you can see is rather insanely big at 9.7 GB, so I'll remove it. Counterintuitively I can't uncheck the check box next to that entry, however, but instead need to select that item, then click "-" immediately below it. I'll also remove my music backup since I don't need to store those on the Internet-based backup device (and, frankly, the online LifeAgent space is pretty expensive, though there's rumor it might drop down soon).

Now that I've expunged (deleted) the backup entries I don't want (and reduced the backup requirement from 13GB to 323MB in the process), I'd like to add a new folder to the backup queue, one that I have put in the Documents folder and that I have named "Backed Up", knowing that if I simply drop files therein, they'll automatically be replicated on my LifeAgent online backup.

This is done by pressing the "+" symbol on the settings window, which reveals:

You can choose any of a ton of preset backup lists, including "all music files", "all photos on the drive", and so on, but since I have my own file, I want to click on "Folders" on the very top, rather than "Smartpicks". It opens up a standard file selection window, so you'll want to navigate to the folder that you want to back up, as I have done here:

Select the folder, click "Done", and:

Click "Done" one more time, and you should be good to go, with your new folder now automatically being backed up to the backup device of your choice!