The "competitors" (not really) with the iPod

The closest competitor with the iPod is Microsoft's mp3 player called the Zune. Of course, the "monopoly" of Microsoft had to have some response to Apple's success. Lol. The Zune plays music, videos, and displays pictures. It is available in 4, 8, or 80 GB versions. There is built in FM radio and it syncs to your computer wirelessly. These last two features I know are not on my iPod. My iPod is about two years old though. Far better models and technologies are available on the more recent models. The Zune comes with some software which contains its own media player to install on your personal computer. Like the iStore, there is a Zune marketplace where users can purchase music and videos, and have access to podcasts. The Zune has all of the options available on a basic iPod. There product came on to the scene a little late though. The iPod has clearly gained the stronghold on the mp3 player market and it doesnt look to be changing anytime soon.
For more info on the Zune, go to their site here.

I will mention a couple other players that may be of interest to you. The Creative Zen and the San Disk Sansa.
The recently released Zen X-Fi is available in 16 and 32 GB versions but allows for extra memory via SD cards. It has wireless connectivity to devices, has FM radio with 32 presets, allows instant messaging with friends, comes with high quality earbuds, and the X-Fi technology supposedly makes the music play with more detail and clarity. Check out this player here.
The San Disk Sansa is obviously made by San Disk, the manufacturer of the often used memory cards/disks. As with the other players, the Sansa is available in various models according to what you are looking for in your digital experience. The Sansa View has larger screen and is best for viewing pictures and watching video. It is very thin, fits in your pocket, and also allows for more memory storage via SD card slots. The Sansa players work along with the media program Rhapsody. This can be installed on your computer along with the player when purchased. On their website, there is a "marketplace" as well with access to music, videos, and games. Check out their site here.

There are many great mp3 players out on the market nowadays. You could not go wrong with any of the above mentioned, but remember, iPod has the stronghold on this type of electronics. Apple continues to grow in popularity and I don't think they will be going anywhere but up in the recent time to come.