I've been closely following this thread. AMPatric, are you an electrical engineer? Your knowledge suggests so.
For many months now DCS-932L and DCS-930L (wireless network camera) owners have been looking for an alternate (longer) power cord, but no one has had the wherewithal to understand the specs and suggest an alternative (the cord is very thin and quite short). If you have the time and would care to take a look at the specifications, here are the product pages:
http://mydlink.com/product/DCS932L
http://mydlink.com/product/DCS930L
Thanks. . . 
I couldn't find the specification for the power brick for the DCS930L - you'll have to look at the OEM power brick to see what D-Link used. The DCS932L uses a 5 volt 1.2 amp power brick - tip polarity and size is not specified - so again, you'll have to look at the OEM power brick.
When searching for a replacement power supply, I use the following guidelines:
1. The output voltage and output polarity (AC or DC on the tip) MUST be the same as the OEM supply.
2. I usually like to go a little higher on the maximum current output (the amps). I generally go 20% higher (50% higher if the OEM power brick runs warm). For the DIR-857 (which had an OEM power brick rated at 12 volts 2 amps, I choose an industrial quality power supply rated at 12 volts 2.5 amps).
3. I normally choose "universal input voltage" switching power supplies (the most common these days) rated to run using an input voltage of anywhere between 100 volts and 240 volts.
4. The "tip" size (inner diameter, outer diameter, polarity (+ or -), and length) need to be compatible with the power input socket on the device that needs to be powered. You many need to use a caliper on the OEM power brick to get these dimensions. If the polarity is not marked, then you need to use a voltmeter (multi-meter or VOM) to find out.
5. I prefer a "brick" style power supply rather than one that plugs directly into a wall socket. However there are cases where a wall mount might works better.
If I cannot find a power supply that has a suitable "tip" in terms of size or polarity (+ or - on the tip) or if the length of the output power cord is not enough, I order up additional wire and a proper size tip. I cut off the original tip, splice on as much wire as I need to get the length I want, and carefully solder on and internally insulate the new tip. You need to be careful to insure you have the right polarity on the tip and good internal insulation when you do this. You should also have a multi-meter (voltmeter and ohm meter) to test you work before you plug-in. Note: After soldering and before screwing the cover onto the new tip, I test with a voltmeter and if all is well I use silicon sealer to "goop around" the solder joints and fill the inside of the screw cap. I then screw on the cap and let the sealer set before using. The solder connectors on these tips are so small and fragile that they easily bend and short circuit unless you do something like this. I have never had any problems after having discovered the silicon sealer trick.
Having said this, there are power bricks available that have interchangeable "tips" with switchable polarity and some even have switchable output voltages. So if you don't do soldering and don't understand multi-meters, then this may be the solution for you. Just insure that whatever "universal" power brick you select has adequate output current (the amps) to power the device and that you can "switch in" the exact same voltage and polarity as the OEM power brick. Note that these universal power bricks tend to be fairly pricey.
In terms of suppliers, a "Google" search for a power brick specifying the "volts" you need should easily turn up a couple of hundred.
I have always found "DigiKey" to be a supplier of quality components. You can find their list of power bricks at: www.digikey.com (or www.digikey.ca if you live in Canada like me). Look in the section called "Product Index" -> "Power Supplies - External/Internal (Off-Board)" -> "AC DC Desktop, Wall Transformers". Since they carry over 4000 different types, you'll need to fill-in the filter to limit the search. The best way is to do this is to select the "output voltage" you need and select a range of maximum currents (example: for an OEM power brick rated at 2 amps, I would select everything between 2 amps and 3.3 amps maximum current output). This normally brings back a page or two of possible power bricks. You can then look at things like tip configuration, polarity, cable length, tip size, price, manufacturer, etc. and then make your choice.
Hope this helps...