Bidland
I worked for the startup bidland.com for a very short time. That said, I worked with some interesting technologies. They had their own server-parsed scripting language there, called BidlandScript. I was involved in HTML design there. Sadly, Bidland was unsuccessful in their endeavors to outsource auctions for individual websites in a way that would keep them in business. The pool table they had for the developers did not make up for the long hours and their fail to execute.

BidLand (2000)

EduPoint
I worked for more than a year at this startup. I worked on a team of professionals building a search engine for classes. Ultimately this company failed to produce results, but I gained experience with server-side technologies such as Perl::Mason and Unix.

EduPoint (1999)
HTML, CSS, Perl, Perl::Mason Programming

ARCO
Well, ARCO was not a startup, but it was where I first did server-side programming with Perl CGIs. It was a dilbert-esque environment, but I learned a great deal -- about programming -- and about corporate culture. For six months I worked on the Corporate section of ARCO's worldwide intranet. I was hired to do HTML and Web Design. I worked on intranet projects, updating the company web site, converting financial documents to HTML at a time when PDF was not as pervalent as it is now.

ARCO OES (1998)
Original Design, HTML, Perl "Wizard"

GTM.net
My first professional web job was for a company called GTM, located in Los Angeles, California. They were a largely unsuccessful company, but I had a wonderful time being paid to experiment with the technologies which were then cutting edge: JavaScript, Flash, Frames, DHTML, CSS. GTM focused on the powerful technologies of Microsoft Internet Explorer at a time MSIE was not the dominant browser.