what is this url?
pcp01595747pcs.taylor01.mi.comcast.net

Hello sammyt.

The URL isn't really a URL.  It is a hostname, the human readable name
given to an IP address.  Decoding hosnames goes from the right to the
left.  The hostname supplied decodes as follows:

.net = Top level domain, one of the original six used on the Internet
and originally intended to be used by organizations involved in the
operations of the Internet.  .net is operated by VeriSign who is in
charge of all second level domain registrations.

.comcast = Second level domain.  In this case a quick check of the
WHOIS database shows .comcast to have been registered to:

   Comcast Corporation (COMCAST4-DOM)
   1500 Market Street
   Philadelphia, PA 19102
   US

You might recognize this company as one of the large cable TV
corporations.  They also provide cable modem Internet access.  As
registrant of the domain Comcast Corporation may create and assign any
further subdomains.

.mi = First subdomain.  This is purely an organizational delegation
that allows Comcast Corporation to classify the use of the IP.  In
this case .mi is the 2 letter state abbreviation code for Michigan.

.taylor01 = Second subdomain.  This is also just for organization.  in
this case the word used is comprised of 2 different pieces of
information.  Taylor is a city in Michigan near Detroit.  The 01
indicates the first and/or primary POP (Point of Presence) in Taylor,
MI for Comcast Corporation.

pcp01595747pcs = Unqualified hostname.  This is the specific name of
the IP address, 68.41.148.213.  It is considered an unqualified
hostname due to there not being any domains or subdomains associated
with it.  By itself an IP address cannot be determined.  In some cases
this is a meaningful name such as "mail" or "ftp", common server types
found on the Internet.  Other cases, such as this one, it is simply a
random name to allow for forward and reverse DNS lookups.

The meaning of this hostname cannot be derived by anyone who does not
have access to the customer records of Comcast Corporation.  If you
wish to know to whom this hostname was assigned you need to contact
Comcast Corporation and request this information.  The best method for
this was found on the Comcast Corporation's Abuse Policy page:
http://comcast.comcastonline.com/memberservices/abusepolicy/default.asp

If you have any further questions please don't hesitate to ask.

Search strategy:

Whois lookup performed by the BW Whois perl script:
http://bw.org

Remainder of information supplied by personal knowledge.

this was an instructional answer for me.