Also see - 25 Twitter Tools for Exceptional Social Results
Here comes GMAIL in for the Rescue
Gmail has a fabulous feature which can help me in creation of multiple Twitter accounts with same gmail email address. let's take a simple example how gmail has created your multiple addresses while you are thinking that u have only one email id. My email address : hiralove@gmail.com - this was the email which I created when opening the gmail account. But gmail gives me few extra emails as well. Like h.iralove@gmail.com , hi.ralove@gmail.com, hir.alove@gmail.com, hira.love@gmail.com, hiral.ove@gmail.com, hiralo.ve@gmail.com, hiralov.e@gmail.com If you haven't noticed .. there is a full stop or dot in different positions for all the consecutive emails above. If you send an email to any of the addresses written above, they all will reach me for sure. But Twitter reads all these emails differently and it will allow you to make the accounts with each and everyone. So from this simple technique I can open 8 Twitter accounts & all will be attached to my same email id i.e hiralove@gmail.com Some of you might be thinking it can also be done with other email addresses but I personally use gmail and I like to use only one account for saving my time to log into different mail accounts. Hope this trick will be helpful for you.Also see - Social Media Monitoring Tools for Power Users
Update: One of my friend (Shivendu Madhava) told me you can get 8 more accounts on twitter with googlemail.com extension which will also be linked to my same gmail account .. thanks to him for the update.