Not too long ago, I was complaining that the majority of Twitter clients was progressively leaving older versions of Mac OS X behind. Also thanks to changes in Twitter’s authorisation methods, most clients today support Mac OS X 10.5 Leopard at the very least, and the lack of clients for earlier versions is maddening, since my Power Mac G4 Cube, for instance, is perfectly capable of running a simple Twitter client.
Yesterday, by complete chance, I discovered Twit Menulet, and when on its home page I read Twit Menulet runs on Mac OS X, Version 10.3.9 and above, I couldn’t believe my eyes.
You’ll find detailed information on how to use it in the manual, but the basic idea is ingenious: as the name suggests, Twit Menulet resides in the menubar as a menulet (or menu extra). If you have enough screen real estate, Twit Menulet displays each tweet in your timeline right in the menubar, like a stock ticker. If you don’t (or if you find the constant updating too distracting), you can tell Twit Menulet to display only the avatar in the preferences.
What’s more, the latest version of Twit Menulet works also as a Tumblr client.
Here’s a screenshot of the application running on my PowerBook G3/400 Lombard with Mac OS X 10.3.9:
As you can see, Twit Menulet offers a wide range of options and actions, and it’s by no means a crippled or ‘simplified’ client. Perhaps some people won’t like the basic concept of it being a menu extra, and prefer to have an always-visible timeline. However I think that, especially on older Macs with smaller screens, this is a more practical, less distracting solution.
Twit Menulet costs $8, but there’s a trial version available for download. Give it a try, and spread the word. A developer who still supports older PPC Macs is surely worthy of praise.
System Folder 
You could upgrade your lombard to tiger. You can even speed up your lombard with a G4 upgrade! I would’ve kept panther on my iBook clamshell, but web browsing on unsupported web browsers is a pain.