This is a list of currently known ftp servers as the time of the OSREV release:

Main server in Canada:
ftp://ftp.openbsd.org/pub/OpenBSD

Argentina:

ftp://ftp.openbsd.org.ar/pub/OpenBSD (Buenos Aires)

Australia:

ftp://mirror.aarnet.edu.au/pub/OpenBSD (Canberra)
ftp://ftp.au.openbsd.org/pub/OpenBSD (Melbourne)
ftp://ftp.it.net.au/mirrors/OpenBSD (Perth)
ftp://ftp.planetmirror.com/pub/OpenBSD (Sydney)
ftp://ftp.wiretapped.net/pub/OpenBSD (Sydney)

Austria:

ftp://gd.tuwien.ac.at/opsys/OpenBSD (Vienna)
ftp://mingus.wu-wien.ac.at/pub/OpenBSD (Vienna)

Belgium:

ftp://openbsd.rug.ac.be/pub/OpenBSD (Ghant)

Canada:

ftp://ftp.ca.openbsd.org/pub/OpenBSD (Edmonton)
ftp://gulus.usherb.ca/pub/OpenBSD (Sherbrooke)

China (Hong Kong):

ftp://ftp.shellhung.org/pub/OpenBSD

Czech Republic:

ftp://ftp.openbsd.cz/pub/OpenBSD

Denmark:

ftp://sunsite.dk/mirrors/openbsd

Finland:

ftp://ftp.fi.debian.org/pub/OpenBSD
ftp://ftp.jyu.fi/pub/OpenBSD (Jyvaskyla)

France:

ftp://ftp.fr.openbsd.org/pub/OpenBSD
ftp://ftp.bsdfr.org/pub/OpenBSD
ftp://ftp.club-internet.fr/pub/OpenBSD

Germany:

ftp://ftp.de.openbsd.org/pub/unix/OpenBSD (Berlin)
ftp://ftp.freenet.de/pub/ftp.openbsd.org/pub/OpenBSD (Duesseldorf)
ftp://ftp-stud.fht-esslingen.de/pub/OpenBSD (Esslingen)
ftp://ftp.leo.org/pub/OpenBSD (Muenchen)
ftp://ftp.fh-wolfenbuettel.de/pub/os/openbsd (Wolfenbuettel)

Greece:

ftp://filoktitis.noc.uoa.gr/pub/OpenBSD (Athens)
ftp://ftp.duth.gr/pub/OpenBSD (Thrace)

Hungary:

ftp://ftp.fsn.hu/pub/OpenBSD

Ireland:

ftp://ftp.esat.net/pub/OpenBSD (dublin)

Italy:

ftp://ftp.openbsd.it/pub/OpenBSD (Napoli)
ftp://ftp.volftp.mondadori.com/mirror/openbsd

Japan:

ftp://ftp.jp.openbsd.org/pub/OpenBSD (tokyo)
ftp://ftp.netlab.is.tsukuba.ac.jp/pub/os/OpenBSD (Ibaraki)
ftp://ftp.kddlabs.co.jp/OpenBSD (Tokyo)

The Netherlands:

ftp://ftp.calyx.nl/pub/OpenBSD (Amsterdam)
ftp://ftp.nl.uu.net/pub/OpenBSD (Amsterdam)
ftp://ftp.nluug.nl/pub/OpenBSD (Amsterdam)

Norway:

ftp://ftp.inet.no/pub/OpenBSD (Oslo)
ftp://ftp.uninett.no/pub/OpenBSD (Oslo)

Peru:

ftp://ftp.sajinet.com.pe/pub/OpenBSD

Russia:

ftp://ftp.chg.ru/pub/OpenBSD (Chernogolovka)
ftp://ftp.radio-msu.net/pub/OpenBSD (Moscow)
ftp://ftp.openbsd.ru/pub/OpenBSD (Novosibirsk)

Saudi Arabia:

ftp://ftp.isu.net.sa/pub/mirrors/ftp.openbsd.org/pub/OpenBSD

South Korea:

ftp://ftp.snu.ac.kr/pub/BSD/OpenBSD (Seoul)

Spain:

ftp://ftp.rediris.es/mirror/OpenBSD (Madrid)

Sweden:

ftp://ftp.luth.se/pub/OpenBSD
ftp://ftp.stacken.kth.se/pub/OpenBSD (Stockholm)
ftp://ftp.sunet.se/pub/OpenBSD (Uppsala)

Switzerland:

ftp://sunsite.cnlab-switch.ch/pub/OpenBSD (Zurich)

Taiwan:

ftp://openbsd.csie.nctu.edu.tw/pub/OpenBSD
ftp://openbsd.nsysu.edu.tw/pub/OpenBSD
ftp://ftp.tku.edu.tw/pub/OpenBS (TamSui)

Thailand:

ftp://ftp.kmitl.ac.th/pub/OpenBSD

United Kingdom:

ftp://sunsite.org.uk/Mirrors/ftp.openbsd.org/pub/OpenBSD (London)
ftp://ftp.plig.org/pub/OpenBSD (London)

USA:

ftp://gandalf.neark.org/pub/distributions/OpenBSD (Batesville, AR)
ftp://ftp5.usa.openbsd.org/pub/OpenBSD (Redwood City, CA)
ftp://ftp3.usa.openbsd.org/pub/OpenBSD (Boulder, CO)
ftp://mirror.csit.fsu.edu/pub/OpenBSD (Tallahassee, FL)
ftp://ftp.src.uchicago.edu/pub/OpenBSD (Chicago, IL)
ftp://rt.fm/pub/OpenBSD (Lake in the Hills, IL)
ftp://archive.progeny.com/OpenBSD (Indianapolis, IN)
ftp://ftp7.usa.openbsd.org/pub/os/OpenBSD (West Lafayette, IN)
ftp://mirrors.netnumina.com/openbsd (Cambridge, MA)
ftp://ftp.groupbsd.org/pub/OpenBSD (Hillsborough, NC)
ftp://ftp.cse.buffalo.edu/pub/OpenBSD (Buffalo, NY)
ftp://ftp.op.net/pub/OpenBSD (Ambler, PA)
ftp://carroll.cac.psu.edu/pub/OpenBSD (State College, PA)
ftp://mirrors.rcn.net/pub/OpenBSD (Fairfax, VA)
ftp://openbsd.secsup.org/pub/openbsd (Fairfax, VA)
ftp://ftp.tux.org/bsd/openbsd (Springfield, VA)
ftp://mirror.cs.wisc.edu/pub/mirrors/OpenBSD (Madison, WI)


As well, the file ftp://ftp.openbsd.org/pub/OpenBSD/OSREV/ftplist
contains a list which is continually updated.  If you wish to become a
distribution site for OpenBSD, contact <miod@openbsd.org>.