Below is a howto on flashing a Netgear WNDR3700 (v2) with DD-WRT.
DD-WRT is a Linux based alternative OpenSource firmware suitable for a great variety of WLAN routers and embedded systems. The main emphasis lies on providing the easiest possible handling while at the same time supporting a great number of functionalities within the framework of the respective hardware platform used.
The reason why I decided to do this was due to the original Netgear firmware obvioously having issues. The 2.4GHz WiFi was both extremely slow and very unstable, and with the latest firmware upgrade from Netgear I was forced to do something. The result was remarkable. After DD-WRT was installed on the router all WiFi issues were solved.
But please do note (src):
There has been some reports of very weak radios (both 2.4GHz and 5GHz) after flashing DD-WRT, but there is also reports of weak wireless with those that never flashed DD-WRT. The issue seems to be faulty hardware, a fairly large bad batch off the assembly line (see "fix" below). Owners with this problem report the wireless is so weak one can't move any further away from the router than 1 meter. A chart has been made by a WNDR3700 owner that is linked at the bottom of this page, you have over 85% chance to get a good working router. See this thread on netgear forums for some low S/N information: http://forum1.netgear.com/showthread.php?t=54442
According to this thread TA numbers ending in 01R15 are likely to be bad. 01R17 are better, 07R18 is 50/50, and it appears 01R21+ are usually fine. Anything starting with 02R is from the "2nd generation" and no issues have been reported with the 2.4Ghz/5.0Ghz bands.
Great result after flashing, went from 3.41 mps to 17.54 in download speeds, and 1.73 to 10.71 in upload speeds. This got me wondering if somehow my router from before had been compromised by someone...
For a detailed guide on how to flash this router please check this page.
Note that for v2 of the router (the version number is found under "Maintainance > Router Status" in the original interface) you have to downgrade the original firmware to 22.214.171.124 before flashing. This can be downloaded from this page.