With 3G or edge, its been noted that battery life decreases dramatically if you are logged onto Conversations (gtalk, skype, etc)

Fring handles the protocols on their servers so they have full control of the data-packets to/from your phone. On s60, its known to be the most battery conservative IM program.

Anyone here beta-testing Fring?, how stable is the current beta Fring for n900 to judge battery life? No way to estimate much better it will be for conserving battery

My guess is they are waiting for the next n900 firmware with latest QT so they don't have to waste time re-writing and to have a single version for Symbian/Maemo....

One word: Pidgin

When doing IM you need a active connection. In Wlan no problem, but with Edge or 3G it is like have an active phone call.
Every phone goes down with a running connection.

The N900 handels it very good I think.

Yeah.... except that Conversations uses most of the same plugins that Pidgin uses, so... no. When I got rid of all Jabber-based IM platforms, Skype and IRC (which I never receive IMs from anyways), my bandwidth usage dropped dramatically.

Fring is a relayed IM solution, hence it should theoretically increase the battery life as it can use longer/custom ping periods and send/receive the data for multiple servers in a single package/burst. However, I prefer a non-relayed solutions (i.e. talk directly to the servers) not just because of security, but also the speed and control and then there are services that do not allow relayed connections (for example IRC servers might reject multiple connections from the same IP, tho I don't remember if Fring even supports IRC). Skype should at least get a bit better when it comes to battery consumption in the following months - they promised they'll optimize and trim their protocol for mobile usage (mainly they will not use mobile devices to relay their transfers to the third parties and such wasteful procedures not suitable for mobile usage). As for the others, there is not much space in improving any Jabber-like protocol (gTalk for example), so one has to learn to live with it. The optimization can be made on the Telepathy itself, tho - while protocols cannot be shaved much, it could at least do some micro-managing and relaying so that it sends all the packets in one burst instead of waking up the connection randomly with each protocol requesting it...

As for the protocols, IRC is probably the most wasteful of them all (not data-wise, at least not if you are keeping away from large channels) and if you have serious power issues when on 2G/3G data connection, you should try disabling that one first. MSN probably comes in second of the widely used wasteful protocols, tightly followed by Skype and Jabber/gTalk. Paradoxically, AIM/ICQ is quite well suited for mobile usage, as long as one does not try to use multiple accounts (at least until local relaying is not implemented within the Telepathy itself).