Programming Tips - How can I get the first (space-delimited) field?

Date: 2009jul1 Language: awk, bash OS: Linux Q. How can I get the first (space-delimited) field? A. The awk command/language is great for this. For example:
awk '{print $1}' /var/log/httpd/access_log
will take a line like this from the Apache log:
192.168.100.200 - - [28/Jun/2009:01:09:51 -0400] "GET /abc/def.html HTTP/1.1" 304 - "-" "Firefox/1.0 (compatible; Win32; I)"
And give you:
192.168.100.200
You can pipe the result to sort:
awk '{print $1}' /var/log/httpd/access_log | sort -u
to find all the unique IP-addresses recently.