So there is, or perhaps there was, a brouhaha over landmarks, and whether they'll go away in favor of something else. Frankly, I wouldn't mind if there were something else, at least in addition to the current landmarks.
Why? As it stands, a landmark has two things: something you really don't care about (sim, x, y, z), and something you do care about (the thing that you want to be able to get to again, or rather some text and an image that describe it). Once you create that landmark, it can become obsolete at any time, because the thing you care about can be moved. Businesses move. People move, or more accurately, their homes do.
When that happens, if you're lucky, someone will give you a new landmark that you can keep--and then you should find and delete the original, assuming you remember to. If you neglect that task, I hope you have your inventory displayed in chronological order or can remember which is the current landmark.
Of course, often those landmark updates will be embedded in a group notice. If you get many of those, you may fall prey to a common mistake: continuing a sequence of clicks on the same response once too often ("OK, OK, OK, OK... oh !#$%@!")... and isn't there a limit on how many pending notices you can have?
Better to have a landmark that doesn't directly contain the (sim, x, y, z) values, but instead points at one that does. (For that matter, the pointed-at landmark could have the image and text, too, so all the new "landmark" need have is the object ID of the real landmark. After all, maybe the store owner remodeled as well as relocated.) Then it's up to the store owner or whoever gave it out to update the single pointed-at landmark, and everyone having a "landmark" that points to it has up-to-date information without having to catch a message, save a new landmark, and delete the old one.
I'd also like an SL client that takes action to let me avoid redundant landmarks ("You already have a landmark that refers to a spot just X meters away from there--do you really want to clutter your inventory by saving this one, too?") and helps me organize landmarks ("Do you want this saved in an existing or new subfolder of Landmarks, or just in Landmarks?"). It's as easy to lose track of landmarks as it is to lose track of one's web browser bookmarks; landmarks have no particular advantage in that respect.
(Let's not get started on the way people abuse Picks, OK? Some other mechanism ought to be in place for non-landmark items, be they your Significant Other, BFF, what you consider acceptable behavior in roleplay, your store's policy on refunds, gifts, etc., ad infinitum.)