Adding Maps and Powers to Skill Challenges in D&D 4e
Skill challenges are a good way to resolve an encounter without fighting, but they suffer from a lack of meaningful choices on the part of the players. Either you're trained in a relevant skill and use it, or you don't and sit out (standard skill challenges) or try and get lucky enough to contribute a success (obsidian skill challenges). The end result is everyone just rolls their skills until they succeed or fail without much more interesting happening mechanically. If you're using the stock skill challenge system, I highly recommend that you check out Obsidian Skill Challenges for a more inclusive skill challenge. The major difference, is instead of X successes before 3 failures, which encourages NOT participating if you don't have a high enough skill value, it's X successes before 3 rounds, which encourages everyone in the party to participate.
Adding maps to your skill challenge works a lot like combat encounters, but you treat it a bit like a board game. The map itself is the location of the skill challenge, whatever it may be (city streets chasing after a villain, a crashing airship as they perform emergency repairs, you get the idea), and the scale of the map is dependant on how you want it to play out tactically. For some sort of chase challenge, or a crime scene investigation, or anything in which player positioning and maneuvering is important, you'll want to treat it just like a combat encounter map. Consider the following map I used for a skill challenge in the Talenta Plains on Eberron:
In this challenge the PCs are attempting to escape from a T-Rex as it chases after them and a pack of dinosaurs. Since how the PCs decide to move is important (as it is the focus of the challenge) I use a scale much like I would a combat encounter. If this was a more abstract challenge, like information gathering in a large city, I might just make a map of city districts that the players move between, rather than a detailed street view. The major goal you should try to accomplish when determining map scale is having PC positioning matter. Too zoomed in and there will be large gaps of useless space where it doesn't really matter where the PC stands, too zoomed out and those important locations disappear. It should ultimately be a worthwhile choice for your PCs to make to determine where they're standing.
In the next step of the Talenta Plains challenge I had to put in obstacles. Obviously the T-Rex is the main thing to avoid, but it shouldn't be as simple as moving in a straight line away from it, so I created hazardous terrain and adversaries (the pack of herbivores that are also running away). The other dinosaurs don't provide a direct threat, but since they're bigger than the PCs getting in their way as they also run from the T-Rex would result in getting trampled, causing the PC to lose a healing surge. If you're doing a city-wide search they could be guards, if you're chasing a villain through streets they could be hapless bystanders getting in the way. The adversaries will move around on the map just like the PCs and provide some sort of threat for getting too close, whether it's a penalty to their roll or health lost, their main purpose is to hamper the PCs as they try to accomplish their goal. Hazards work similarly, but are immobile, and should debuff the victim rather than directly harming. Going back to the dino chase, getting caught in the mud would slow a PC for a turn, webs would immobilize, ledges and rocks would require an acrobatics roll to avoid tripping. When investigating a crime scene, using Nature to identify the killer's tracks won't work as well on the hard packed dirt as it would on the mud.
Finally, you're ready for the actual skill rolls and movement on the map. Instead of having the skill roll be the only action a PC can do on their turn, instead give them a standard action and a minor action, enough for a skill roll and/or power use (more on that below) as well as some sort of minor option. A successful skill roll should allow the PC to move, either their speed (on a 1:1 scale) or 1-2 squares, while a failure only allows them to move half that or less (on a 1:1 scale, two squares like if they were slowed works best). Going back to movement options, there should be ample motivation to want to move around; for example in a city-based skill challenge, moving to a tavern square could give a +1 benefit to streetwise for a turn, and mobile adversaries also help to motivate.
Power usage is a bit more abstract and ruling it should be up to individual DM interpretation. The basic guideline goes that relevant encounter and daily powers should enhance the action being taken. If the power grants movement, allow the PC to move 1 extra square for an encounter power or 2 extra squares for a daily power. If the power grants a free attack, allow an ally to make another skill roll for an encounter, or another skill roll with a +1 bonus for a daily. If the power uses forced movement, allow them to use it on an adversary to get them out of the way. If it grants a power bonus to attack or damage, grant a power bonus to the skill roll. Each power will need to be handled on a case by case basis, but the basic idea is to morph the result of the power into something similar that's relevant to the skill challenge, and give a +1 for encounter powers or a +2 for daily powers. If they want to use a power as-is without modifying for the skill challenge, you should let them do that too, but have it use up their standard action without making a skill roll - this allows them to directly attack adversaries or objects for some sort of large secondary benefit.
Essentially, you're creating a very quick board game: you have your pieces, you have squares to move to, and you have special squares and pieces that either hamper or help that you try to collect or avoid. All of this is happening in parallel to your primary objective, which is to accumulate successes, and all the effects of moving around on your map should result in either helping or hampering in that goal. For an example of this sort of thing, check out my custom skill challenge: Don't Wake Sentries.