I'm currently playing in a long-running D&D campaign, and DMing a second. Both are 4th Edition games. One thing that has started to stand out to me is that the "Curse of the Wizard" has subsumed all classes in this new edition. In previous editions, the wizard, and to a lesser extent all spellcasters, had to treat their arsenal of spells like a precious commodity, only to be expended in times of great need. This led to a built-in limit on how long a party could continue adventuring without resting. Once the wizard had cast all his spells, he began whining about taking an 8-hour rest (now we call them "extended rests") and this led the party to try to find a defensible position and hope that their DM was kind enough to allow them some sleep. In 4th Edition D&D, now even the fighter and the rogue (traditionally the two classes that could keep going right up to their last hit point) are asking to take a rest every third encounter. At the lowest levels, this doesn't appear to be horribly problematic, but when your party has infiltrated the enemy's encampment and are stealthily disposing of the strongest pockets of resistance, it becomes difficult to justify huddling down in an empty tent for six or eight hours!
So, what to do? We want to keep the game exciting, and we want to make sure that there are plenty of reasons to take extended rests, but is there a way to extend the amount of time a party can continue toward their goal? For DMs, this is even a way to retain suspense and build tension, because nothing kills the tension and excitement like a group of players afraid to do anything because they are out of daily powers and surges.
The first potential solution is to create a median between Short Rests, about 5 minutes of in-game time long, and Extended Rests, which are at least 6 hours long and must be seperated by 12 hours of activity. We'll call them Moderate Rests, lasting at least 30 minutes. A moderate rest should refund one daily power, and a quarter of the character's healing surges. Moderate rests should not be allowed more than once every two milestones (four encounters) in heroic and paragon teirs. Once the characters have hit epic teir, don't allow a moderate rest until three milestones (6 encounters) have elapsed.
If you feel that the real stumbling block is simply the fact that the effectiveness of the characters drops off too steeply when all daily powers are expended, consider giving the option of recharging a daily power instead of receiving an action point. This option should be restricted in some way, because players may choose to abuse such largess on the part of the DM. First, make sure that the character does not have an item which awards action points for some circumstance. No matter how unlikely the circumstance, this could lead to all players seeking out such items, and would mean that the players are not truly giving something up to gain another use of their daily power. Second, once the character has more than one daily power, consider restricting this option to only when they have two fewer than their maximum number of daily powers. This way, you won't have a character who is able to bring themselves back to a full compliment of daily attack powers by forgoing action points.
If you are open to something a little more drastic, a more significant adjustment to the system would be to boost the number of healing surges each character has, and to recharge daily powers half as often as you award action points. Take the final number of surges for each character and multiply it by 1.5 to give the total number of surges. Every four encounters, let the characters choose one expended daily power and return it to their "unused" pile. This system will allow for more encounters within a single day of game time. It might also unbalance the characters slightly against the level progression model of the core rules. If you use this option, consider slowing down the XP gain, perhaps by awarding only three quarters of the original experience. However, you might find that no balance problems arise, and if they do not, avoid instituting any penalties for the system.
Remember, the purpose of these rule options is to increase the number of encounters a party can tackle before running out of gas and needing some sack time. It's about increasing the entertainment factor, and keeping the game running smoothly. If you aren't having any problems with that, don't try these out, as they will simply tend to unbalance the game and potentially could ruin everyone's fun. However, if you're like me, and hate having to try to take a quick 6 hour nap in the Antechamber of Death's Dwelling because the four encounters getting to the antechamber, and then the fight with the red dragon in the antechamber, have completely wiped out your attack powers and healing surges, perhaps these slight tweaks might help to alleviate some of those problems.