November 2008: I am using OpenBSD 4.4 on an IBM T20 laptop. The installation was easy and the OS works very well. Xorg works without any configuration, audio works fine, the internal ethernet interface works, and my Atheros 802.11 PCMCIA card works. What follows below are the steps I followed.

Install all package sets from the installation CD.

Add these lines to the end of /root/.profile:

PKG_PATH=ftp://ftp.openbsd.org/pub/OpenBSD/4.4/packages/i386
export PKG_PATH

Install a bunch of packages to make a comfortable environment. Some of these packages are large, so if you are on a slow network, it will take some time to complete.

pkg_add -i bash icewm mozilla-firefox xpdf mplayer

Create a non-root user account and put this in their .xinitrc file:

xsetroot -solid gray20
exec icewm

Install other packages that one might need, such as LaTeX:

pkg_add -i texlive_base

RTFM and get help from the guys on the #openbsd IRC channel on freenode.

Update (December 2008): I have found OpenBSD 4.4 to be rather buggy. The kernel panics or hangs easily with USB events. The filesystem implementations are not robust. OpenBSD is the least stable operating system I have used in the last ten years. FreeBSD and Linux remain my preferred operating systems.