Jajah also has a downloadable plugin for the mobile phone which can be handy when it works, but is generally more trouble than it is worth.
However, Jajah have obviously recognised the problems with the plugin and come at the issues another way – they have setup a site at mobile.jajah.com. You access this site from your phone’s browser and make your calls from there.
No messy plugin to download and because most of the work is done server-side, very few client-side (handset incompatibility) issues.
This is a great idea – it certainly will make the process of making many calls from your mobile cheaper and easier than using the plugin. However if Jajah were trying to make the process easier for their clients, why not reduce the amount of typing required (everyone hates typing on phone handsets)? Why not make the address m.jajah.com?
You can see a demo of the app working here.