I used to have to carry reams of enlarged text across campus because I couldn't afford a screen reader. The only large magnifier was in the University Library. Back then having a portable screen reader was prohibitively costly. Now it seems like magic thanks to products like Prizmo from Creaceed. I can perform A scan using your iPhone's Camera. Perform OCR, Optical Character Recognition and then perform Text to Speech in 10 Languages. Each Voice is an in App Purchase but I am sure well worth it. Here's a Demo Video: http://www.creaceed.com/prizmo/iphone/presentation.html
Prizmo is also available on the Mac OS X Ver. 1.5.6 Snow Leopard Only. Prizmo for IPhone is compatible with the 3gs and the iPhone 4. There are other solutions offered by other Software developers so feel free to shop around. If you need this technology to overcome reading printed text then a Mobile OCR with Text to Speech will fit the frugal budget!