New Media Guides

"Being portable suggests that the devices are battery-operated so system power consumption is a key concern. Portable audio devices may include integrated audio codecs or audio ADCs and DACs for conversion between analog signals and digital data, headphone or speaker drivers for earpieces, headphones or built-in speakers, programmable DSPs for encoding/decoding compressed data in formats such as MP3, WMA or AAC, microcontrollers for handling system-level control and user interface functions, and wireless transceivers for transmission/reception of data over RF (radio frequency)."
Given that technical description of portable, let me give you some examples of units I know work well or have had good reviews.

• M-Audio MicroTrack 24/96 - a mobile 2-channel digital recorder that records WAV and MP3 files to CompactFlash. It has balanced line inputs and microphone preamps. There is phantom power for studio-quality microphones. You just connect it to either a PC or Mac with a USB connector.  It has a lithium-ion battery that charges via the computer’s USB connection or USB power adapter. I am a bit concerned about not being able to change the battery if it ever dies but I am hearing that M-Audio handles replacement well. If you know about inputs at all, it offers 1/4", XLR, and S/PDIF inputs which is nice. You can get one of these for around $350 if you shop around.
• Edirol R1- I have heard good things about this recorder as well. Scott from the podcast "Tokyo Calling" uses an Edirol and has much luck with its performance and durability. It has built in mics that do well. Another version which is more expensive but is the newest news with Edirol is the R-9
• Edirol R9- This is the newest version. I had one comment saying it was also a great unit.
• Zoom H4 - also a 24/96 recorder, this one has a better price and I think it looks great. I would like to try it out if I buy another one for my CompTech8 class new media projects. It is $299 on the website so I know you can get it for much less! The cool part is you can record 4 track whereas the others are only 2 track. It has 2 combination XLR-1/4-inch input jacks with phantom power so you can use it with any microphone. It has studio effects like compression, limiting and mic modeling in the unit.
• Belkin Voice Recorder for iPod - plugs right into your iPod for voice recording. It provides a quality similar to USB microphones. A little bit muffled but not bad. This is due to limited frequency response -  it does not capture the higher and lower ends of our voice's audio spectrum. At $50, it is a great way to have an instant mobile recorder if you already own an iPod!
• iRiver