Me and my gaming group have a set of cheap, plastic poker chips (costing around $1.50) which we mostly use for our Savage World games. They come in three colors: white (the most abundant), red, and blue.
Now in the first sessions of 4E D&D that I ran, it didn't occur for me to use the poker chips. Players kept track of their healing surges, their marks, and their action points. For the second game, I thought to use the poker chips to keep track of all three elements. I distributed white poker chips to keep track of healing surges (and the Defenders had such a huge stack!), red chips to keep track of marks (we had both a Fighter and a Paladin in our game), and blue chips to designate action points.
This proved to be a good idea as I was running a huge group (seven players with all but the Warlock class covered) and the poker chips not only made it easier for me to keep track of everybody's conditions (i.e. the Paladin went through most of his healing surges by the time we ended the game) but it also gave an abstract concept (healing surges and action points) a tactile feel to the players.
I noticed a boost in game play the second time around. First, the white chips helped players gauge how much damage they were receiving. The party's Paladin was complaining at how he was down to his last two white chips but was congratulated by the rest of the party because theirs was mostly untouched and that he was covering his role quite competently. Second, because I was GMing for a huge group, I was similarly throwing a lot of monsters against the players. The red chips helped me keep track of which monsters were marked and which weren't--and this particular fact becomes helpful when you're running anywhere from half a dozen to a dozen monsters at a time. In many ways, the red chip also informed players who weren't paying close attention which monster was getting hit and who to focus fire on (the color red simply screams "hit me"). Lastly, there were the blue chips. In the previous session, few players used their action points, and only after a few reminders from myself. In this session, I didn't need to plod them to do so (and in fact some used action points at times I never would have--such as to kill a surviving minion) and the blue chips reminded them that they had such an option. Dispensing of action points was also as simple as me "rewarding" them with chips and them returning the chips to me whenever they expended it.
The usage of poker chips, while not required, enhanced my D&D game: it's a shiny thing players get to hold and play with while as a GM, it also enabled me to keep track of what was going on the table. Of course the design philosophy I used for poker chips doesn't have to be limited to keeping track of healing surges, marks, or action points. By using index cards to keep track of Powers for example, the same effects can be reproduced: players hand to their GM their Encounter Power cards whenever they expend them and they get returned once the encounter is over (same goes for Daily Powers except they're returned after an Extended Rest). This theoretically discourages indecision paralysis (less cards in their hand means less options to choose from) and reminds them of some of the resource management involved in the game.
Does all this make Dungeons & Dragons feel more board game-y? Perhaps but my main priority is what would make the game more fun. And tactile components (just don't go too overboard with them) are a great way to remind and entice players into the game.