SoundHound and Shazam are amongst the most popular music recognition apps out there and the former has just upped the ante on Shazam.
SoundHound, has updated the free version of its Android app to allow for an unlimited number of music IDs, a significant increase from the previous limit of 5 per month. Shazam's app currently functions in a similar manner but still maintains the limit of 5 music IDs per month. If you're on a shoestring budget, the choice between the two is probably a no-brainer at the moment.
From now on though, both the free and the paid versions of SoundHound for iOS and Android will let you tag an unlimited number of songs. The freemium model will contain ads, while the paid app won't.
In addition to recognizing songs, SoundHound is also able to recognize hums and your attempts at singing any song you'd like to know the name to. Lyrics also show up in-app, you can perform a music search by voice, and you can also buy tracks from within the app.
SoundHound is also available for Nokia Symbian smartphones, but only in paid form.