Debra, one way would be to setup a command line or php tool that lets you specify which user to use. For example, with the code example above you could make multiple copies of the command line tool, one for each account and each tool would have the user/pass for each account. Instead of naming the program “twitter” when yous ave it you could do like twitterchrispian and twitter451press (my two twitter accounts, for example). They’d be the same other than user:pass. So then when I sent a message for 451 press I’d just change the command from twitter to twitter451press and it would use that script.

I’ve seen an example of a php script that interfaces with curl to send tweets. I’d imagine you could set it up to use multiple accounts too.

If you are on windows, there are also like 5-6 twitter clients and you could run one of each for each account.

I see. Then using multiple clients, which you can install on windows or a mac should work fine. I use Twitteroo and TwitBox, though there are more. Ive started a list (I’ll be adding to it) http://www.twitterhacks.com/twitter-clients/

But you can run two different clients, 1 for each account. I also run twitter on firefox for one account and a twitter client for my main account.