MiScope Handheld Digital Microscope ,$275

Features
View live and capture images on the computer screen (or use a computer projector for large groups)
40 — 140x magnification
Completely portable with a laptop computer
Save still images, movies and time lapse
Labels, markers, time stamps, measurement
Draw directly on the live image
Includes Video ToolBox Software


http://www.zarbeco.com/products-misc.shtml

5X-500X 1.3MP USB Digital Microscope with LED Light ,$65

Features
Digital image treatment and micro-measure tool digi-Microscope
Microscope lens with 3 stage zoom
This brilliant magnification tool plugs directly into your computer without the need for batteries
Built with 8 LED's to make sure you always get the best captured image
Can adjust the lamp brightness
Jewel decoration design is very fashion

http://www.tmart.com/5X500X-13MP-USB-Digital-Microscope-with-LED-Light_p115442.html

Porta-Trace / Gagne Porta-Scope Handheld Digital Microscope ,$230

Microscope Type Digital monocular
Eyepiece Not applicable
Objective(s) 10-200x
Focuser Helicoid (broad green barrel)
Light Source 6 USB-powered LEDs
Light Control Yes
Specimen Stage None
Dimensions Not Specified by Manufacturer
Weight Not Specified by Manufacturer

http://www.bhphotovideo.com/c/product/614886-REG/Porta_Trace_Gagne_SCOPE_Porta_Scope_Handheld_Digital_Microscope.html

USB Digital Microscope (1.3MP, 200x Magnification) ,$60

This USB Digital Microscope is a fully functional magnification tool that plugs directly into a computer for up to a 200x magnified view of objects. This allows you to see even the smallest of details, in high definition, directly on your computer screen. Details like individual strands of hair or even the fine scratches on a collectible coin that would be impossible to detect with the naked eye, can easily be viewed by this amazing USB digital microscope.


http://www.chinavasion.com/product_info.php/pName/usb-digital-microscope-13mp-200x-magnification/

USB Digital Microscope with 200x Magnification--reviews

To be honest, this product is probably OK for the price, but not more. The optics are primitive, as is the PC software.

There is no separate focussing facility. To focus, you must first set the magnification level you want, then move the microscope towards or away from the subject until it comes into focus. You may need to repeat this process a few times until the picture is as you want it.

Focussing at the both extremes of the magnification is quite tricky, and at large magnifications there are actually two focal points.

Maybe this is par for the course for USB microscopes, but to be honest I was a bit disappointed, whilst still recognising that it's probably what you should expect for the price.

Carson zOrb Digital Microscope-Safari Green ,$29

The MM-480 zOrb from Carson Optical is a Digital Microscope with an integrated camera that displays the magnified image right on your computer screen. The impressive 35x Magnification (14" monitor) allows you to see details of ordinary objects you never knew existed! The built-in internal illuminator ensures a clear and bright image. The zOrb Digital Microscope comes in 3 colors: Surf Blue, Safari Green and Lava Orange. Capture an image to keep using the built-in 640 x 480 resolution digital camera. You can even capture close-focus video with the zOrb! The zOrb is compatible with Microsoft Windows 98SE, ME, 2000, XP, XP Service Pack 3 Upgrade, Vista and MAC OSX 10.4 or later. A USB 2.0 port is required.

http://photo.net/equipment/store/product?pgid=757915084

Carson zOrb Digital Microscope ,$32

Microscope zOrb 35x MM-480

http://photo.net/equipment/store/product?pgid=752426404