SeeqPod, a "playable search" product born in the UC's Lawrence Berkeley National Laboratory, offers music search that scours the Web for music in both audio and video formats. Upon finding music you can play it immediately and add it to a playlist which can then be embedded into other pages like the playlist I quickly pulled together below. Songs and playlists can be shared via email or embedded into other sites. In fact, I learned about SeeqPod from a friend of mine, David Robinson after he shared a playlist and was enthusiastic about the product.
Not only does SeeqPod allow you to search, it also allows you to discover new music. Clicking the discover button rather than search will bring back recommended music based on the song you placed in the text box. I am not sure how SeeqPod is creating recommendations but it reminds me of iTunes "Just for You" music recommendations. Check out the screen-shot below of the discover search results. Additionally, SeeqPod offers API's for developers to tap into the Recommendation and Discovery Services.
SeeqPod is similar to JiwaMusic but SeeqPod offers a sleeker, icy interface and pulls in both audio and video options for the various search terms. SeeqPod also works great on the iPhone for on the go use.
Bottom-line: SeeqPod offers a slick application for searching, playing and sharing music on the Web.