The venture arm of Indian operator Reliance has joined T-Mobile Ventures as an investor in US startup Pelago, the company said Tuesday.

Pelago is another microblog / wireless social network, which is not the only similarity it shares with Twitter. This latest round of funding also takes its current war chest up to $15m.

But the US firm is interesting in that its product, Whrrl, is still in beta. The service, which is only presently available in some US cities, allows users to locate their friends as well as geo tag locations and add comment. These tags would then become accessible to other Whrrl users, and could be used for restaurant reviews etc., or so the company says.

Apparently Pelago will use the funds to drive its expansion into Europe and Asia.