Cool idea, Mike.

Heres what I’ve got installed:

$ gem list|grep '^[a-zA-Z]'

action_profiler (1.0.0)
actionmailer (1.3.2, 1.3.1, 1.2.5, 1.2.4, 1.2.0)
actionpack (1.13.2, 1.13.1, 1.12.5, 1.12.4, 1.12.0)
actionwebservice (1.2.2, 1.2.1, 1.1.6, 1.1.0)
activerecord (1.15.2, 1.15.1, 1.14.4, 1.14.0)
activesupport (1.4.1, 1.4.0, 1.3.1, 1.3.0)
acts_as_ferret (0.3.1)
acts_as_searchable (0.1.0)
ajax_scaffold (1.0.0)
an-app (0.0.3)
ar_mailer (1.1.0)
aws-s3 (0.3.0, 0.0.8952)
badger (1.0.1)
bfts (1.0.0)
BlueCloth (1.0.0)
builder (2.0.0)
camping (1.5)
capistrano (1.3.1, 1.2.0)
capistrano-ext (1.0.1)
cgi_multipart_eof_fix (2.0.2)
color-tools (1.3.0)
daemons (1.0.3, 0.4.3)
Dependency (1.0.0)
dhaka (2.0.0, 1.0.0, 0.0.6, 0.0.5, 0.0.2)
dnssd (0.6.0)
fastercsv (0.2.0)
fastri (0.1.1.1)
fastthread (0.6.2)
fcgi (0.8.6.1)
feedtools (0.2.26)
ferret (0.10.14, 0.10.13)
fjson (0.0.8)
flexmock (0.2.1)
gem_plugin (0.2.2, 0.2.1)
greenbar (1.0.0)
gruff (0.1.2)
highline (1.2.3)
hobo (0.4.3)
hoe (1.1.6, 1.1.4)
hpricot (0.4.59, 0.4)
icalendar (0.97)
insurance (0.3)
junebug (0.0.12)
keyword_search (1.0.4)
libxml-ruby (0.3.8)
markaby (0.5)
mechanize (0.6.4)
memcache-client (1.0.3)
metaid (1.0)
mime-types (1.15)
miniunit (1.0.0)
mocha (0.3.2)
mofo (0.1)
mongrel (1.0.1, 0.3.13.4)
mongrel_cluster (0.2.1, 0.2.0)
mylib (0.1.0)
mysql (2.7.3, 2.7)
ncurses (0.9.1)
needle (1.3.0)
net-sftp (1.1.0)
net-ssh (1.0.10, 1.0.9, 1.0.8)
newgem (0.2.0)
paginator (1.0.8, 1.0.6)
ParseTree (1.6.3, 1.6.1)
payment (1.0.1)
pdf-writer (1.1.3)
piston (1.1.1)
production_log_analyzer (1.3.0)
query_builder (1.0.0)
rails (1.2.2)
rails_analyzer_tools (1.1.0)
railsmachine (0.1.2)
rake (0.7.1)
raspell (0.0.1)
rbayes (1.0.0)
rcov (0.6.0.1)
RedCloth (3.0.4)
RedGreen (1.0)
rmail (0.17)
rspec (0.6.4)
ruby-breakpoint (0.5.1)
ruby-growl (1.0.1)
ruby2ruby (1.1.1)
rubyforge (0.3.1)
rubygems-update (0.9.2, 0.9.1, 0.9.0, 0.8.11)
RubyInline (3.6.1)
rubyosa (0.2.0, 0.1.0)
RubyToC (1.0.0.5)
rubyweather (1.0.0)
ruport (0.4.0)
selenium (0.6)
Selenium (1.0.0)
sendfile (0.9.2)
session (2.1.6)
sources (0.0.1)
sqlite (2.0.1)
sqlite3-ruby (1.1.0.1)
streamlined_generator (0.0.4)
sup (0.0.5, 0.0.1)
svn_conf_generator (0.0.3)
sydparse (1.2.2, 1.2.0, 1.0.0)
syntax (1.0.0)
tattle (1.0.1, 1.0.0)
termios (0.9.4)
Text (1.1.0)
THERuSH (0.9)
transaction-simple (1.3.0)
tzinfo (0.3.1)
unicode (0.1)
uuidtools (1.0.0)
vpim (0.360)
win32-service (0.5.0)
xml-simple (1.0.10)
ZenTest (3.4.3, 3.2.0)

What do you have installed?