O2 UK has announced the expansion of its in-store 'Guru' technical help service to the internet. O2 Guru TV is a YouTube video channel offering advice that helps customers get the most from their mobile technology.

The free service is open to everyone and currently includes over 400 videos, with over 50 new videos being added every month.

Telefónica O2 Ireland and the eircom Group have announced a new mobile network sharing arrangement in Ireland. Between them, the two companies are responsible for services using the O2, Tesco Mobile, Meteor and eMobile brands.

They'll be consolidating cell sites where possible, working together to provide and maintain site equipment.

There won't be mobile phone coverage on the London Underground in time for the London 2012 Olympic and Paralympic Games. It's reported that the issue of funding has caused talks to collapse.

However, plans to roll out WiFi to over 100 tube stations are going ahead.

O2 says it's the first UK network to take advantage of Ofcom's new rules about redeploying old GSM frequencies. It's now reusing its 900MHz spectrum in London for 3G services, which is apparently delivering a 50% increase in capacity to the existing 2100MHz 3G network.

O2 has also deployed so-called 3G900 services in Leeds, Birmingham and Manchester.

In The Fonecast this week we discuss mobile termination rates, traffic management for mobile broadband, smart meters, protests, applications and crime-busting ringtones.

We also talk about the Japanese earthquake, which - although it's predominantly a human tragedy - also has economic consequences for the mobile industry.