[dorkbotpdx-blabber] Arduino - reading digital pins as a number?

[Hans Lindauer]

A few easy questions for those in the know.  I have a DIP (SIP, 
actually) switch connected to pins 5-8 of my dorkboard(s) and to +5V, 
and want to read in the switches as as number.

1.  Can I safely connect +5V to a digital input (or 4), and leave it 
high for an extended period without having to worry about overheating or 
other issues?  Probably a dumb question, I know, but I'm still learning 
the ins and out of this stuff.

2.  Do I need pull-down resistors to ground on each of the digital 
pins?  I guess I don't understand the necessity of that.  Also, is my 
terminology correct?

3.  What's an elegant way to read those pins in as a byte?  I know I can 
multiply the pin value by 2^n and add them all up, but it seems like 
there's got to be a smarter way.  Maybe I can read a register with the 
pin values and mask off those bits?

Thanks in advance,
-Hans