How to use multiple Google / yahoo account at same time

I am sure many of us might have faced this problem when you have two separate accounts and want to use it at the same time for example when you have 2 yahoo mail accounts one professional and one personal or when you use seperate login for Flickr and yahoo mail similarly when you have different account for google, youtube and Orkut. Which means each time you have to logout and login to check another and this annoyance continues.

The solution is simple since the way login is maintained over a period of time is by cookies so simply use different Browsers! By using different browsers you can login to same service with different account without affecting cookies of each other.

There are quite a few to choose from FireFox (www.firefox.com), Opera(www.opera.com), Flock(www.Flock.com), Safari(http://www.apple.com/safari/).

I first faced this problem with orkut and blogger. Since google consolidated login to different service using same google account with cookies it is very annoying for people who don't same google account to use all services. For example the account I use for Orkut is different from the Google account I use to login to blogger.Due to these I had so many times mis-posted using wrong id without even realizing it.

Did you ever had such incidents ?