Quick, grab some eye protection, it’s the world’s most expensive MP3 player, and it’s encrusted with more than 400 diamonds (over 4 carats). Over the last couple years, Thomas Heyerdahl, a Norwegian jeweler, has produced a handful of these glitzy gadgets, some of which have been auctioned for charity. When it comes to MP3 players, this golden Apple accessory is a bit out of budget for most: $40,000+!

Heyerdahl also likes to put the Midas touch on cell phones. He received some attention last year for his similarly blinged-out Nokia 8800 cell phone.

You know, if you can’t afford the $40K iDiamond MP3 player, perhaps you could spring for the diamond earbuds to go with your Nano? Comparitively speaking, they’re a bargain, and available separately, for just over $6,000. Here’s the iDiamond video.

With gas at $4 a gallon,is it really possible to get an MP3 player for less than $20? I went on a search for the lowest priced, most affordable MP3 players around, and here’s what I found:

The Nextar MA 323 (shown above) is a 1-inch cube that you can put in your pocket or wear around your neck. For a mere $14.99, the Nextar MP3 player, available at J&R, includes 128 MB of storage space and an FM radio receiver. In case your wondering, 128 MB of storage equates to about 2 hours of MP3 playback.

Next up in my search for MP3 players under $20, we have the Hydra MP3 made by Ultra. With this one, you get 1 GB of memory, and it’s splash resistant. The Ultra Hydra supports WMA file format, and there’s a built-in FM receiver and voice-recording option. The Hydra MP3 player is listed for $16.99 at Tiger Direct.

And, finally on my list of MP3 players under $20, we have the refurbished Sansa Express 1 GB MP3 player. Also available at Tiger Direct, the Sansa Express is a flash based MP3 player. It supports WAV, MP3, and WMA files, and even includes a micro SD slot for expansion- all for $16.99.

Wait!! Don’t throw out those stacks of old cassette tapes just yet. Seems that dusty Janet Jackson Rhythm Nation tape from 1989 (what were you thinking?) might still be good for something.

This cassette tape to MP3 converter plugs into your personal computer or laptop to convert all those cassettes into files you can use on your MP3 player, or other MP3 playing gadgets like cell phones or PDAs.

Tape2PC, made by ION, comes with Audacity software for Mac and PC, and MixMeister for converting cassette tapes directly to iTunes. Here’s a thought- once you have your cassette files on your computer, you could easily burn them to CDs.

Tape2PC comes with a USB cable, stereo RCA cable, and software. I found it at Same Day Music for $140.

Hey Star Wars fans- here’s something to add to your collection.  This R2-D2 USB hub has four slots for plugging in all your favorite gadgets like a cordless mouse, your MP3 player, or your Blackberry.  The USB hub even makes those famous sounds that make R2 as endearing as any little robot can be (includes an on/off switch).  This new gadget comes with a USB cable, and it works with Windows XP or later, and Mac OSX or later. The R2-D2 USB hub is set to be available in October, and it’s available for preorder at Play-Asia.

If you want a hub that’s a little more sinister than R2-D2, you can always go with this Darth Vader USB hub.  It also has 4 USB slots, sound effects, and comes with a USB cord.  The Darth Vader USB hub is also available for preorder at Play-Asia.

Here’s an innovative idea for your iPod Nano- Bluetooth headphones. IMuffs let you put your iPod in your backpack or your pocket and listen to your tunes without wires in the way. The iPod headphones are compatible with any iPod that has a dock hookup on the bottom, and they’ll function up to 30 feet away from your iPod using Bluetooth technology.

There are controls on the ear pieces, so you can change songs or the volume without digging out your MP3 player. IMuffs are available at Balkowitsch Enterprises for $175, and they’ll also work with any Bluetooth cell phone.

If you’d rather have iPod earbuds instead of headphones, have a look at these EarPollution earbuds made by ifrogz. The colors are great, the radioactive symbol is very unique, and they include a travel case. Depending on what you use them for, you should check out both the short cord and long cord versions. I found ifrogz EarPollution earbuds at DayDeal for $18.99.

With a 160 GB memory, the Archos 605 media player offers a lot of storage space for media files including videos, photos, and music.  The handheld media player has a 4.5 inch LCD screen, and Wi-Fi capabilities (additional plug-in needed).

The Archos 605 is 0.6 inches thick and a full battery charge will give you 16 hours of music play time, and 5 hours of video playback.  What I like the most about this media player is that you can view PDF files with it. There are several optional plug-ins for the Archos 605 including a cinema application and Podcast plug-in.  There’s also the option to buy or rent media from Archos via the media player.

The Zen MP3, made by Creative Labs, is a 4GB MP3 player with a lot of cool built-in gadgets and features.   The MP3 player, measuring a mere 3.25 X 2 inches (approximate), includes a built-in FM radio with 32 presets, a voice recorder, microphone, and an alarm clock.  The Zen MP3 holds up to 1000 songs, and it has 8 EQ settings, including acoustic, digital, jazz, disco and more.  It also has a slot for an SD card and you can get up to 25 hours of play time on a single charge.  And, if you’re into staying organized, the Zen MP3 syncs with Microsoft Outlook and includes a USB cable.  The Zen MP3 retails for around $99.