Greg is correct; there's no need for CAT5e at all in a residential environment. In fact I'm using the white/orange and white/brown pairs in my "CAT Nothing" voice cables at home to connect to my switched hub/router with no trouble at all. Unless you have a situation where huge file transfers between computers will be an ongoing issue, basic Internet access can easily be accommodated using CAT3 or less.
CAT3 cable was designed to carry data speeds of up to 16Mbps, 60% more than a DSL or cable modem connection can provide anyway.
It's all about hype generated by manufacturers to sell more wire, and more expensive wire at that. Let's not forget those insanely-priced "wiring management centers" that all of the manufacturers want you to be scaring people into buying. With their line of thinking, you should also be wiring every receptacle in the house with a home run of 8/3 Romex on a dedicated AFCI 20 amp circuit, a 6,000 amp three-phase service and you should have ten ground rods driven in the yard.
While such an installation might not "look" proper to those who claim to be "pros", electrically they are fine. Is it possible that you might get an occasional instance where ringing voltage might distort a data packet or two? Of course! That's why computer networks check the send/receive status of data packets and resend them if they don't receive a confirmation that they were received. That's how the Internet and TCP/IP networks were designed to operate. A human will never know if a data packet was missed and resent, even multiple times.
Rest assured that people will shoot you down in this theory, but I'm using one of those connections from home right now while I am on this site. I'm also downloading a 600 page manual at the same time and my wife just received almost 300 pictures from our son's wedding a minute ago. I also have three other computers at home and four VOIP phones that we frequently use simultaneously over this same wiring. Don't be afraid to stand out in the pack.
By the way, my company installs these wiring networks as our primary line of work, so I do speak from experience.