Laptop used in multiple network contexts?

[John Whitley <whitley@cse.Buffalo.EDU>]

While the subject of laptop metapackages, etc. is current, I thought
I'd bring up a few topics:

1) What (if any) is the preferred mechansism for preventing Linux from 
   stalling all over the place on DNS timeouts when an otherwise
   network connected laptop becomes laptop-at-large?


2) Is there a mechanism in Linux for easily switching between different
   network situations?  Since I'm running Debian on a new Powerbook, I
   have some experience with a _very_ nice feature in MacOS 8.6: 
   The Location Manager.  For those unfamiliar with this feature, a
   description follows.

In the Location Manager I can create profiles, composed of a
collection of settings for virtually anything network related.  This
goes from basic TCP/IP connectivity, AppleTalk (natch), printer
configurations, to QuickTime default bandwidth settings.

Here are some example profiles:

Home (ppp) -- for direct modem dialup to my ISP using ppp to create
              and manage the TCP/IP link.  QT bandwidth set to modem
              speeds.

Home (CM) -- for direct connection to the cable modem, using DHCP to
             get relevant TCP/IP related info.  QT bandwidth set to
             sky's-the-limit.

Home (housenet) -- fixed IP/nameserver, connected to an IP MASQ'ed network
                   behind the cable modem. 

Work (office) -- fixed IP/ns, my office ethernet drop

Work (NSC 220) -- fixed IP/ns, ethernet port in a classroom I teach in
Work (NSC 210) -- fixed IP/ns,    "      "    " "     "     "   "   "

In each of the above fixed IP setups, the IP, nameserver,
etc. settings are different in each location.

It would be *great* if there was a facility for switching between
profiles like those above, on the fly, for Linux laptops.  Is there a
mechanism already in place for this, or is this a yet another GPL'ed
project waiting to be born?

-- John