Actually you can test two at a time by using an alias in /etc/hosts.
In /etc/hosts:
1.2.3.4 site1.com site2.com
Then you have to edit /etc/hosts to try two more sites.
The idea that the user cannot access /etc/hosts on the iPhone is reason enough to jailbreak it. Denying access to /etc/hosts means the iPhone cannot connect to the any website that requires a hostname, even when the iPhone can connect to the internet, unless the iPhone can access some DNS server (which of course Apple probably wants to control). That is a ridiculous limitation. The internet nor the web requires DNS to work, but the iPhone requires DNS to access the web.[1]
1. assuming the website is using virtual hosts or otherwise requires a hostname
In /etc/hosts:
1.2.3.4 site1.com site2.com
Then you have to edit /etc/hosts to try two more sites.
The idea that the user cannot access /etc/hosts on the iPhone is reason enough to jailbreak it. Denying access to /etc/hosts means the iPhone cannot connect to the any website that requires a hostname, even when the iPhone can connect to the internet, unless the iPhone can access some DNS server (which of course Apple probably wants to control). That is a ridiculous limitation. The internet nor the web requires DNS to work, but the iPhone requires DNS to access the web.[1]
1. assuming the website is using virtual hosts or otherwise requires a hostname