One of the biggest new-media sensations to emerge from last year were music-related widgets - mini-applications that allowed members of social networking services like MySpace or Facebook to customise their profiles with such music features as streamed playlists and tour calendars with links to ticket sales.

What helped the widget trade to boom in the first place was that MySpace and Facebook didn't offer such services to artists and fans directly. But now that MySpace is readying a full-featured music service of its own, and Facebook is rumored to be working on something similar, what happens to all these widgets that filled that void?

It's hard to imagine that MySpace will block these applications once the music service rolls out. The company faced a harsh member backlash last year after it started blocking widgets, and it joined Google's OpenSocial initiative specifically to give developers the tools needed to write applications for MySpace that can also work on competing social networks.

So if MySpace doesn't block overlapping services, what happens then? Here's a quick snapshot of the main services MySpace Music plans to offer, the existing providers of the same and how this might shake out in the months to come.

Artists on MySpace can already stream songs in full, sometimes entire albums in advance of their release, as long as their label gives the OK. However, MySpace members haven't had the ability to construct and stream their own playlists from their profile without outside help. The leading widgets that enable MySpace users to do so are imeem and Last.fm.

Both are social networks in their own right that have capitalised on MySpace's usical foot-dragging to lead the way in online free streaming, and both are targeting MySpace's audience.

It's unlikely that MySpace will rely on either to power its internal playlist/streaming features, particularly as it's not that difficult a service for MySpace to build on its own.

To date, Snocap's MyStores widget is the only official download-to-own application on MySpace. The site has blocked other third-party applications in the past. (Most notably Indie911's Hoooka app, chaffing MySpace celeb Tila Tequila when she tried to use it to sell her debut release.)

But the MyStores widget proved a bit of a flop. Slightly more than 100,000 of MySpace's 5 million artists embedded the store on their profile, and few sales followed. What's more, rival imeem has since acquired Snocap - likely to add its own download-to-own service as well.

Expect MySpace to either terminate its Snocap deal outright or simply wait for member artists to dump the app on their own. MySpace is keeping a tight lid on exactly how it plans to deliver full songs, so any discussion of potential partners is pure speculation.

One option would be a MySpace-branded download service that uses technology from a third party like MusicNet. Another would be to partner with an existing service, in which case Amazon would be the most obvious contender given MySpace's well-established distaste for digital rights management.

Any concert ticketing service will almost certainly have to include Ticketmaster, but the wild card is iLike - in which the industry giant owns a stake.

The No.1 music application on Facebook has very little exposure on MySpace, and as such has little to fear from an overlapping service.

But iLike has grown far beyond its tour-date roots. The company is making a point of getting directly into MySpace's knickers by hosting artist profiles where participating acts can stream music, post videos and more.

REM made headlines by streaming its new album "Accelerate" on iLike rather than MySpace, generating 1.5 million streams in the six days prior to its release.

What's more, iLike syndicates artist pages across a host of participating social networks - including Facebook, Bebo and Hi5- and<