IP address can be changed* in many ways
1) if you are using a dynamic ip connection like dialup or non-static bb, you can request a new ip from your isp by typing "ipconfig /renew" in command prompt..
2) Simple disconnection and reconnection will assign a new ip to your system
3)Other way is to use a proxy..
A proxy is like a intermediate server that forwards your request as it own. Suppose you connect a website say,
www.google.com.
Without a proxy, your computer uses its own ip to request the html,jpeg,etc files for google.com. so your request headder has your ip and agent details + requested files.. So when google sees their logs, they see your ip in their request header. got it?
But..when you use a proxy, all the your file request (Remeber that a webpage actually contains many relevent files) are given to the proxy's ip.. so it then requests the page for you from google.. When google sends the files, it comes first to the proxy and then to you.. So when google sees their logs, they see only the proxy's ip address in the forward header.
But since proxy are now well known ( for some ages).. there are ways for google to get your real ips inspite you use proxies.. The file request header from the proxy top google has your ip also but in diff variable..
So to completly cover your ips you can use different types of proxies..
Like
Transparent proxies - Which has your ip in its header
Anonymous proxies - Which hides your ip in its header up to an extent
Highly anonymous/ elite proxies - Completly hides your ip in all the forward requests..
There are lots of proxy lists available.. But it is a bit hard to get high speed working proxies.. Just google around for some time about proxies, get a proxy pinger ( proxy validator) to check the fasted proxies to your system and use it to HIDE your ip
i think they are the better ways to hide ips without discon..
And also.. If tou want to switch proxies while browsing, use proxy switcher extensin in firefox. it works very well to enter certain sites..
Hope this helps..
P.S. MOST OF THE BB Uses dynamic as there are only a few who needs a staitic ip for certain purpose. To get a static you need to specially pay an added amout/month to get a permanent static ip. Otherwise, all the connections are 90% dynamic