Quoting Steve Litt (slitt@???):

> All of you have also crystalized one of the factors that have pushed me
> away from GPL: The requirements of displaying it.

Which as licensor you are free to waive. Note footer at the bottom of
http://linuxmafia.com/ssh/ as an example:

Copyright (C) 2000-2009, Rick Moen, rick@???.

This information is free; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation, version 2. (Licensor waives GNU General Public
License's requirement to include a copy of the licence text in
redistributions or derivatives of this work.)

[...]
Additionally, copyright owner waives GPLv2's obligation to include a
copy of the licence text if redistributing the covered work or
derivatives thereof.
[...]

Waivers are often useful to dispose of licensing problems.

For example, when I was working at VA Linux Systems, my friend and
co-worker Marc Merlin released for usage there and elsewhere a set of
patches for the Exim MTA to retrofit TLS capabilities (so it could do
SMTPS and all that). It did this through close integration with
OpenSSL.

I brought up on the internal mailing lists a possible problem: OpenSSL
includes both newer code under 3-clause BSD and older code under
4-clause BSD written by original Australian coder Eric A. Young back
when the project was called SSLEay.

The fourth clause in question was the 'noxious advertising clause' that
famously induces GPL-incompatibility in derivative works. _If_ Marc's
work created a derivative of Phil Hazel's Exim MTA with Young's code,
then Hazel might well object and seek to enjoin the work. (This was
back around 2000, before I learned that some FSF claims must be taken
with a grain of salt, and I believe I outright asserted to Marc that he
was inadvertently infringing Hazel's copyright, which isn't actually
clear.)

Marc got angry at _me_, to which I said 'Hey, don't kill the messenger',
and suggested merely asking Hazel if he'd grant a licence exception
prospectively permitting Exim's use with OpenSSL. Marc allowed that
this is a good idea, and he says Hazel was fine with this and
immediately added it to Exim. (On a quick look, I haven't found this,
but am not going to spend more time searching.)

> What methods have you guys used in order to display your GPLv* licenses
> in software with a user interface, as required?

Waive that requirement. You're the copyright owner; you get to make the
rules.