For a lot of D&D groups, the 'normal' progression of loot is just fine. As characters grow in level, they acquire larger hordes of gold, gems, and, most importantly, valuable magic items. Now, I'm not one of those 'low magic' hippies, mind you; I like my cool magical gadgets as much as the next guy. However, what does bother me is the overemphasis on bonuses and metagame statistics. It really takes the mystical feel out and makes equipment a science. At the same time, this is what most veteran D&D players are trained to seek in my experience. This is the 'loot' mentality; if it doesn't have a constant, immediate benefit, it's not worth owning. Below is a short list of tips on how to wean you players from this mentality.

1. Make Magic Items Cool, Not Powerful: Of course it's okay to place a truly powerful magic item in your campaign from time to time, but for the most part, give your players items that, while certainly magical, either provide some nonstandard or nonstatistical benefit. One of item of note that Michael once placed in an adventure was statistically an amulet of natural armor, but its effect was sheathing the wearer in a layer of ice armor and providing a small amount of bonus cold damage to the wearer's unarmed damage. Not a big benefit, but the 'cool' factor made it legendary. Another example might be a variant of a wand of charm person: perhaps it comes in the form of an enchanted flower that the wielder must hold and get the target to smell willingly, but has a bonus to its save DC because of this. The idea is connect the form and function of the item in an interesting way.
2. Make Combat Engaging, Not Difficult: Like the first tip, it's still okay to throw your party a curve ball when appropriate. However, for the most part you're going for combats focused more on the style than stats. If you want your players to stop focusing on stats, though, you need to avoid placing them in situations where they have to powergame to survive, which may mean lowering the difficulty level at first. Think about having your players describe their attacks, and maybe even, once per session, give a fellow player's PC a small bonus on attack or damage when the description is especially awesome. Lastly, give your monsters and NPCs personalities and distinctions; have them speak in combat, taunt the PCs, give them facial expressions, have them cry out to their gods, whatever's appropriate really. Just have them do more than stand there and attack.
3. Give the PCs Things to Buy: And I mean things other than another +1 on a longsword. Houses, servants, food, clothes, jewelry, tattoos, honoraries, favors from locals, legal documents, anything. Maybe the difference between a lawless vagabond and a respected explorer is a well-maintained place of residence in a particular land. Whatever it is, make sure you're giving the PCs plenty of options aside from magic items. On occasion, make nonmagical items necessary to finish an adventure to emphasize their place in the PCs' budget.
4. It's All in the Name: Nothing is more meta than "+1 longsword," and yet, even as we attack all other forms of metagaming, many of us let that one slide. The books give us little recourse for changing how we talk about items distinguished only by the numerical value of their bonus. The solution Michael and I came up with a while ago (along with several other veterans in our group) was to refer to weapons in 'tiers,' so a +1 longsword would be a '1st-tier magic longsword.' This simple language can obviously be easily modified in many different ways, but is good because it both precisely conveys the statistical values of the weapon and seems reasonable as in-game jargon. Avoiding statistical meta-references is important to de-emphasizing them, so this is an important step.
5. Stats Stay in the Background: This goes right along with the last point. Instead of asking for a player for his or her PC's AC or Will mod, make sure you have all the statistical information you need written up on an index card or something similar. The fewer references of this kind, the better.