That's what I do. I rent an empty rack in a hosting company.
Inside the rack, I put:
- Two HP DL380 G5 servers
- Two HP DL380 G3 servers
- Two HP 48-port switches
- Two Cisco CSS load balancers
- One NetApp S500 NAS
It's a huge hassle to deal with all this "stuff" and the rack, power, and bandwidth cost me $1,710/mo.
Shared hosting, virtual private servers, and managed dedicated servers are so much easier.