Here's the 3rd (1st and 2nd) report from Adam Tondowsky on the 2004 election, which deals with 3rd Party performance overall for the Libertarian, Green and Constitution parties candidates:

3rd Party Votes

Total:                     2,668,992
Libertarian:               1,056,582 (145 candidates)
Green:                     361,394   (45 candidates and 1 Ohio 1st CD write-in)
Constitution:              182,849   (43 candidates)
Write In:                  50,087
Others and independents:   1,018,080

Libertarian Party Overview:

The 145 Libertarian Party candidates received 1,056,582 votes. This is down from 2002 when 217 candidates received 1,165,618 votes. The Party ran congressional candidates in 27 states- Alaska, Arizona, California, Colorado, Delaware, Florida, Hawaii, Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, Oregon, Pennsylvania, South Dakota, Texas, Utah, Washington, Wisconsin and Wyoming.

17 Libertarian candidates ran in districts where either a Democrat or a Republican did not run, and did far better than their compatriots. Those 17 candidates received 437,542 votes (an average of 25,738 votes). The 128 candidates that ran in districts where both a Democrat and a Republican ran received 619,040 votes (an average of 4,836 votes per district).

Green Party Overview:

The Green Party ran 45 candidates and 1 write in candidate and received 361,394 votes. This is an improvement for them over 2002 when 58 candidates received 306,819 votes. The Party ran congressional candidates in 16 states - Alaska, California, Colorado, Connecticut, Maryland, Michigan, Minnesota, Nebraska, New Jersey, New York (as Peace and Justice Party), Ohio, Pennsylvania, South Carolina, Utah, Washington and Wisconsin.

Like the Libertarian Party, the Green Party did better in districts where either a Democrat or Republican did not run. 5 Greens ran in districts with either no Democrat or Republican and received 84,115 votes. The 40 remaining candidates (excluding the right in candidate) received 277,081 votes. An average of 6,927 votes per candidate.

Constitution Party Overview:

The Constitution Party received 182,849 votes in 2004. I did not track the party in 2002. The party ran 43 congressional candidates in 15 states - California, Colorado, Connecticut, Florida, Kentucky, Maryland, Michigan, Missouri, Nebraska, Nevada, Oregon, Pennsylvania, South Carolina, Utah, Wisconsin.

They ran under the American Independant Party in California, the Concerned Citizens Party in Connecticut, The U.S Taxpayer's Party in Michigan, the Nebraska Party, The Independent American Party in Nevada, and the Constitution Party everywhere else.

The Party ran in 4 districts where either a Democrat or Republican did not run and received 41,225 votes in those districts. The remaining 39 candidates received 141,624 votes (an average of 3,631 votes per district).

Other:

Formerly 'major' 3rd parties like the Reform Party, the Natural Law Party and the various socialist parties barely registered. The Reform Party only ran candidates in Mississippi and 1 candidate in Kansas, the Natural Law Party ran 1 candidate in Michigan.

Note:

It should be noted that many people who voted 3rd party don't necessarily support the Party, but voted for them because one of the two major parties did not run a candidate in the district.

Here are how individual candidates performed for the three 3rd parties where both a Democratic and Republican candidate were running:

Top 10 Libertarian candidates by percent of vote
in districts where both a Dem and a Rep ran: 

1.Kelley Ross, California 28,         5.7%
2.John Crockett, Arizona 1,           5.2%
3.Herb Peters, California 27,         4.7%
4.Mark Stroberg, California 13,       4.3%
4.Dave Kaplan, Arizona 7,             4.3%
6.Gary Fallon, Arizona 4,             4.2%
7.Jake Witmer, Illinois 4,            3.9%
8.Brian Holtz, California 14,         3.6%
8.Randall Weissbuch, California 26,   3.6%
10.Robert Anderson, Arizona 8,        3.4%
11.Richard Kahn, New Hampshire 2,     3.4% 


Top 10 Green Party candidates by percent of vote
in districts where both a Dem and a Rep ran are 
(6 of the top 10 ran in California. The party ran 
11 candidates in the state): 

1.Patricia Gray, California 12        9.1% 
(This is Tom Lantos' district.  Almost certainly part of her 
vote was a protest against his vote in favor of going to war)
2.Larry Mullen, California 19,        6.7%
3.Jay Pond, Minnesota 5,              5.7% 
(Jay Pond ran for either governor or senate in 2002.  He is 
becoming a bit of a 'star' for the Green Party in Minnesota)
4.Pamela Elizondo, California 1,      4.8%
5.Theresa Dudley, Maryland 4,         4.5%
6.Eric Carter, California 27,         4.4%
7.Bob Kinsey, Colorado 4,             4.2%
8.Timothy Feller, Alaska,             3.8%
9.Thomas Lash, California 46,         3.7%
10.Patrick Driscoll, California 5,    3.4% 


Top 10 Constitution candidates by percent of vote
in districts where both a Dem and a Rep ran: 

1.Dean Wolf, Oregon 1,                3.9%
2.Janie Hanson, Nevada 2,             3.6%
3.David Horn, Michigan 7,             3.0%
(this is the district where a moderate Republican won the 
Republican primary over a number of conservative opponents)
4.Clyde Harkins, Colorado 7,          2.5%
5.George Lilly, Colorado 1,           2.2%
5.Gordon Mego, California 35,         2.2%
7.Dale Winegarden, Oregon 3,          2.1%
8.Dick O'Dell, Nevada 3,              2.0%