Public input is one of ICANN's primary goals, and ICANN has tried a number of different systems over the years; archives for the various public forums are listed below.

Archives of web-based forums.
adhoc Ad Hoc Group on Numbering and Addressing (March 2001)
agreements Tentative Agreements among ICANN, the US Dept of Commerce, and Network Solutions [missing comments]
alignterms Alignment of directors terms (January 2002)
atlarge At Large Membership (March 2000)
atlargebylaws Revisions to ICANN Bylaws on At Large Membership (July 2000)
atlargestudy At Large Study (December 2000)
auda Approval of ccTLD Sponsorship Agreement with auDA (September 2001)
budget Fiscal Year 2000-2001 Proposed Budget (June 2000)
budget0102 Fiscal Year 2001-2002 Proposed Budget (June 2001)
cctld ccTLD Delegation and Administration Policies (March 2000)
cctld2 ccTLD Issues for Discussion at Yokohama (July 2000)
costrecovery ICANN Cost-Recovery Structure for TLD Registries (May 2001)
dnsoreview1 DNSO Review (February 2001)
election Election Committee Recommendations (July 2000)
emergingrirs Criteria for Recognition of New Regional Internet Registries (June 2001)
escrow Registrar Data Escrow (October 2002)
geo Definition of Geographic Regions (July 2000)
gtld Continued Recognition of gTLD Registries Constituency (September 2001)
icng Recommendations of the .info Country Names Discussion Group (March 2002)
indreview Independent Review Policy (March 2000)
minutesbylaws Revision to ICANN Bylaws on Meeting Minutes (July 2000)
newtldagmts New TLD Agreements (March 2002)
newtldevaluationprocess New TLD Evaluation Process (September 2004)
newtlds Introduction of New Top-Level Domains (July 2000)
nsi2001 Proposed Revisions to VeriSign Agreements (April 2001)
offtopic Placeholder Forum for Off Topic Postings
org Reassignment of .org TLD (January 2003)
reform President's Report: ICANN -- The Case for Reform (March 2003)
regfees Registrar Accreditation and Fixed Annual Fee Revisions (June 2001)
regxfer Transfers Between Registrars of Sponsorship of Domain-Name Registrations (March 2003)
riragmts ICANN-RIR Relationship Agreement (December 2004)
selfnomination At Large Elections: Proposed Rules for Self-Nomination (July 2000)
tldapps Forum on New TLD Applications (November 2000)
tldreport Forum on New TLD Applications II (November 2000)
uniqueroot Unique, Authoritative Root for the DNS (July 2001)
wgb Working Group B Report on Famous Names (April 2000)
wgc Working Group C Report on gTLD Expansion (April 2000)

Hierarchical email-based forums

gtld-deletion-comments Comments on the gTLD Deletion Proposals (November 2005)
gtld-plan-comments Comments on A Plan for Action Regarding New gTLDs (December 2002)
old-alac-forum ALAC Public Forum
org-eval Comments on the Evaluation of the .org Propsals
reform-comments ICANN Evolution and Reform Comments
riodejaneiro Comments for the Rio de Janeiro Meeting