If you've been reading for awhile, you may remember that I love Pandora. Free, online radio. No commercials. And it learns my preferences and introduces me to new music. I love it. I feel like online radio has rekindled my interest in music and kept me from being an old fogy, stuck in a time warp of the songs that were popular when I was high school.

There are, however, two things that aren't so great about Pandora. A truly ideal personalized radio station would let you request a certain song and then hear it immediately, rather than simply registering it with your preferences and playing it eventually. It would also let you play your favorites whenever you want to hear them, instead of just leaving you hoping that they'll come on again soon.

If those things bug you about Pandora too, you might want to check out what comes close to an ideal personal radio station: Slacker Radio's Premium service. On Slacker Premium, when you request a song, you can listen to it right away (although you have to know the artist name to search. For instance, if you hear a song you've never heard before somewhere, and you know the title of it but not who sang it...you won't be able to request it on Slacker until you figure out that little bit of information).

My other favorite feature is the "library." Whenever you click the little heart next to a song that you like, it gets marked as a favorite. Slacker Premium automatically saves it to your library, and then anytime you are logged in to Slacker, you can play any song in your library. You can even go to your library and hit "Shuffle Play All" and it will automatically play all the songs you've saved. (You can't save them to your computer or burn them to CDs, though; they're web-based only).

Slacker Premium also offers unlimited unlimited skipping; Pandora limits you to a certain amount of skips per hour. I don't think I've ever actually gone over my limit of skips on Pandora, but it's nice to know that with Slacker Premium, I could skip as much as I wanted to. If I wanted to.

One minor quibble with Slacker; if you hear a song you like, but you're doing something else (like nursing a baby or cooking dinner or changing a diaper or practically anything else I do all day long) and don't have time to stop by your computer and click the little heart to save it as a favorite...then you're out of luck until next time it comes up. I haven't been able to figure out a way to scroll back in the playlist and heart all the songs I liked but didn't have time to heart while they were playing.

Also, if you decide you REALLY love Slacker, you can buy a "Slacker Portable," which is an iPod-like device that allows you to listen to any of Slacker's millions of songs any time. You don't even have to have Internet access; the Portable learns your preferences and then whenever it is connected to WiFi it automatically fills itself up with thousands of new songs. If I was someone who listened to the radio for hours at a time (if I had a long commute, for instance) I might consider getting a Slacker Portable, because free commercial-less radio that I can finetune to my own preferences is just that cool.

Now, the caveat: the Slacker service I've been listening to, the Premium level, is not free. A guy who does PR for Slacker contacted me and asked if I'd be interested in reviewing Slacker Premium, and I said I would, and he enabled an account for me for free. But normally, Slacker Premium is $7.50 per month. The free-level users have only a limited number of song requests (10 per station) and skips (6 per hour per station), and they don't get to save their favorites to their library.

Verdict? Slacker is very cool, and I really like being able to request songs and save my favorites. Would I pay $7.50 a month for the privilege? I don't know. I'm pretty darn cheap. But if you think unlimited access your own personal radio stations is worth it, $7.50 per month is not that much. I've had a great experience with it. Thanks, PR guy, for giving me the chance to try it out!