In one of the recent updates to the Facebook site, the company removed the ability to customize what Recent Activity appears on your Wall. These are little stories of actions you have taken elsewhere on the site, and they are republished on your Wall for your friends to see.
It's worth underlining that your friends can only view your Recent Activity that they can view elsewhere: for example, a wall post you made on a mutual friend's wall or a comment you posted on a photo that both you and your friend can see. In other words, if they cannot the action you made elsewhere on Facebook, they will not see at story of it on your Wall. Of course, you can see everything since you made the actions.
Previously, you could disable this functionality and clean up your Wall with only activity you make on it (status updates) and posts your friends make on your Wall. This functionality was recently removed and users were stuck with whatever they had customized their Walls to prior to the site update. You had to manually remove anything you didn't want on your Wall. Now, the company has brought back the option to automatically hide all current and future stories of a given Recent Activity type. This change can also be reverted if need be.
For example, I have always wanted to remove "Wall posts you make" from my wall. These are snippets of wall posts I make on my friends' walls and I don't want them littering my own wall. Again my friends will still be able to the actual posts I made, and they will still show up as stories in their News feed; they just won't be present not on my Wall.
To remove them, I can now click on the x beside one such story (under Recent Activity on my wall) and choose "Hide all Wall post activity..." from the drop down menu (the other option removes just that post). From there, I am prompted with "Wall posts you make will no longer appear in the recent activity section of your Wall. Edit Options" and can choose Hide all.
Scrolling down, I noticed that I wanted to do the same for comment activity (such as posts on friends' photos) because it was also littering my wall. Other stories you can also hide include Friending activity, Things you like, Platform activity, Questions activity, Changes to your profile, and so on.
The Edit Options link is worth taking a closer look at. If you don't click it when you are making changes to your profile story settings, don't worry as you can still find the link at the bottom of your profile. On the left there is a link to show Older Posts and on the right there should be a link for Edit Options. Clicking the right link opens up a "Edit your profile story settings" window where you can undo the changes you have made.
Notice that it does not list all options in Recent Activity that you can disable, but merely the ones you have disabled. In this way, Facebook is forcing you to only be able to remove types of stories that are currently on your Wall: you can't simply disable everything from ever appearing (I would certainly choose that if I could).
Being able to hide this Recent Activity allows users to engage with more content on Facebook and not have to clean up their own Wall afterwards by removing content they don't want there. It should be particularly useful to Facebook users who are always using the site as well as those who are more sensitive about their actions on the social network being shown on their own Wall.