What could possibly constitute a "zesty" smartphone? We're not sure, but if O2's latest Xda device intends to live up to its name, we're going to find out. An ASUS-sourced handset bearing the "GM5 / Crystal / Xda Zest" name just garnered approval from the Global Certification Forum, and as we all know, anything starting with "Xda" is pretty much a lock to see duty on O2 as a Windows Mobile smartphone. Nothing is known about the thing at this point beyond what the GCF tells us, which ain't much: triband GSM, 2100MHz WCDMA with video calling, and -- you'll never believe it -- it supports "browsing." Hot dog!