Sure SM57s are industry standard for live app. though they get used a lot in studios as they can really take a beating.

They are dynamic mics which means they are not very sensitive. This means they are prone to being noisy and have a very small sweet spot (i.e. you may spend a lot of time getting mic placement right to get the sound you want to tape / disk). The SM57 is also great for high volume (SPL) work. Price point about 100 USD new

A large diaphragm condenser on the other hand is a delicate bit of kit, requires phantom power (from either a mixer, channel strip or in line box) is very sensitive and has a much wider sweet spot (much easier to work with). However these mics are not so good for working at high volume. Price: 60 USD to about 10 000 ! Good if you already have a preamp or mixer.

A USB condenser is probably the answer you are looking for. These guys plug into your computer, have a built in preamp and suck power form the PC. In terms of quality, they are not top of the line however they will give decent results. BLUE make something called a "Snowball"

http://www.musiciansfriend.com/product/Blue-Snowball-USB-Microphone?sku=279015

then these as well:

http://www.musiciansfriend.com/product/MXL-.006-USB-Powered-Condenser-Microphone?sku=273175

http://www.musiciansfriend.com/product/R0DE-Podcaster-Broadcast-Quality-USB-Microphone?sku=270033

and at the other end of the scale....

http://www.8thstreet.com/product.asp?ProductCode=27170&Category=Microphones