A coder by name of ThaKilla has just released a new homebrew DS app of his called DSBlue. It's a work in progress and, as such, DSBlue will no doubt undergo quite a few changes before its final release.

The current version contains the following features (text in italics are direct quotes of ThaKilla):

Wifi Modules
AP Finder (used to find and connect to a local AP)
Packet Spy (used to view data floating in the air, no recording and locks up every now and again)
Port Scan (can scan for open ports on a certian IP)

Shoutcast (does not work really, but the code should help others)
Its needs to be changed from using the sync method of libmad, to a frame based version.
Has support for multiple list (hardcoded at the moment :( )

Scratch Pad (will be removed)
was going to be a simple notepad, but the Calendar should take its place.

Remote Desktop (still a little buggy)
It allows you to connect to a PC (running the server program I made)

Calendar
It allows you to view a calendar and enter in text for a certain day. (this will sync with the PC app soon)

Config
Just pretty much Wifi Settings.

Desktop Sync (not implemented yet)
Will be used to sync up information between your DS and PC (mainly for the calendar at the moment, but will also include other settings)

DSBlue is a tight-looking little application, and we're certainly looking forward to future updates. We do hope that the Shoutcast feature gets implemented in a later release though, because we think that's a rather nice little feature to have on our DS.