The main aim of webmasters is to bring lot of traffic to their sites and increase their Google Page rank.
But they can easily check their traffic from the cpanel stats or similar scripts like google analytics , stats counter and so on.

For checking Google pagerank , there are also a lot of online tools like :

Google toolbar for IE and Firefox,
Pagerank.net
iwebtool.com - To check predicted PR
Prchecker.info
checkpagerank.com
SEOchat.com - lot of SEO tools
livepr.raketforskning.com - check live pagerank in various datacenters
Live pagerank - addon for mozilla firefox

and so on….