dsniff was great, but in ruby it ought to *shine* more.

Original dsniff was:

 * arpspoof  - Send out unrequested (and possibly forged) arp replies.
 * dnsspoof  - forge replies to arbitrary DNS address / pointer queries
               on the Local Area Network.
 * dsniff    - password sniffer for several protocols.
 * filesnarf - saves selected files sniffed from NFS traffic.
 * macof     - flood the local network with random MAC addresses.
 * mailsnarf - sniffs mail on the LAN and stores it in mbox format.
 * msgsnarf  - record selected messages from different Instant Messengers.
 * sshmitm   - SSH monkey-in-the-middle. proxies and sniffs SSH traffic.
 * sshow     - SSH traffic analyser.
 * tcpkill   - kills specified in-progress TCP connections.
 * tcpnice   - slow down specified TCP connections via "active"
               traffic shaping.
 * urlsnarf  - output selected URLs sniffed from HTTP traffic in CLF.
 * webmitm   - HTTP / HTTPS monkey-in-the-middle. transparently proxies.
 * webspy    - sends URLs sniffed from a client to your local browser
               (requires libx11-6 installed).

The idea is to reimplement everything and have it behave just like the original
dsniff did.