The Linksys WRT54G and the WRT54GS are popular popular wireless broadband routers. One things that sets them apart from the rest is that they run Linux.
This means that a whole community has sprung up dedicated to hacking the WRT, as it is known. They are trying to cram a whole lot of functionality into a box that was not built for it, the essence of hacking.
Here are two sites that suggest the latest packages and modules for the WRT:
Openwrt.org seems to have very complete documentation. Modules includes iptables, kismet, OpenSSH and the like.
batbox.org had a bit more of a homegrown feel to it but still seem to be the reference.
A good this seems to be that the install is to the ram disk so that if you screw things up, you just have to power cycle the box.
There is also a company called Sveasoft that sells, for 20$US, a replacement firmware and support for both these routers. Some of the features added can be found here.
Following up on Tin Titan's post regarding public DNS servers here is a list of Public Proxy Servers. Usefull if a website is going gergraphic-ip filtering.
In case you find an open wireless AP that has DNS turned off, or for any other reason that you can't contact the local DNS, here is a list of Public Name Servers that you can use.
This article hits the main points in locking down a wireless access point:
1) Change Default Administrator Passwords (and Usernames)
2) Turn on (Compatible) Encryption
3) Change the Default SSID
4) Enable MAC Address Filtering
5) Disable SSID Broadcast
6) Assign Static IP Addresses to Devices
7) Position the Router or Access Point Safely
It's not a technical howto but a good guide of what you should be paying attention to when securing your AP.
This is a small app from Google that sits in your system tray and notifies you when you have new incoming messages in your GMail account, without having Internet Explorer or any other browser open. You can download it here.
BMail from BeyondLogic.org is a simple command line mailer for Windows that is useful for doing windows batch files that need to send mail. You can download it here.
It has few options but they are just the ones you need: mail server, to, from, subject, body (command line or from a file) and a debug mode.
If you download the additional Mpack (file here, README here) you can add MIME encoded attachments to Bmail by following the instructions on the Bmail site.
Very simple, no setup, just unzip the executables and write your batch files.
NetStumbler is the de facto Windows tool for remotely analyzing a wireless network. It sniffs out 802.11 a/b/g connections, finds out if they are open or not and retrieves all the info it can from the access point. It even records the signal strength and the geographical coordinates (if you have a GPS receiver plugged into your computer).
It is a handy tool to check out what your own access point looks like from the outside once you finished setting it up. It is also very popular for War Driving.
You can also download MiniStumbler, a smaller version made for wi-fi enabled handhelds that run WindowsCE.