The prizes will be presented at the 13th annual Webby Awards Celebration June 8 in New York.
All of the Special Achievement Award winners are expected to accept their honors in person, organizers said on the Webby Web site.
Reznor was declared the Webby Artist of the Year for the debut of his album "The Slip" as a free download on his Web site last May.
Fallon will be honored as the Webby Person of the Year in recognition of his enthusiastic embrace of the Internet to connect with his fans.
Twitter won the Webby Award for Breakout of the Year. Accepting the award will be Biz Stone, co-founder of Twitter, who is recognized for his creation of the micro-messaging service that has grown in use by 900 percent in the past year.
Silverman has been named Best Actress in recognition of her popular YouTube music video, "I'm (expletive) Matt Damon," and for "utilizing the political power of the Internet" with "The Great Schlep," organizers said.
Kudrow won the Webby Award for Outstanding Comedic Performance for the Internet series "Web Therapy," which she stars in, co-writes and co-produces and which airs on lstudio.com.
Seth MacFarlane won the Webby Award for Film and Video Person of the Year in recognition of his Cavalcade of Cartoon Comedy animated videos distributed through Google's content network and on sethcomedy.com.
Also to be honored at next month's ceremony are NPR, NYTimes.com, Digg, NBC.com, Next New Networks, The Onion, YouTube and the BBC, Information Week said.