I have never heard of this service before until Wojitas mentioned it to me. It looks like a new BlackBerry application that makes a backup of your contacts on their servers and lets you share content with services like YouTube, Facebook, and more.
They have a free and premium account option but I cannot really recommend the premium account except for one feature. It lets you restore all of your contacts back to your BlackBerry more than once a year. I guess this is targeted at Europe due to the prices only being in Euros but it is definitely worth a look if you want a free solution for backups… Though you could always use Google Sync…
Personally I think that if you are willing to pay you would be better served with a hosted BES solution or SmrtGuard at the very least.
Check it out at www.pleex.com and let me know what you think. You need to register on their site from your PC/Mac first before you can download the app.