stream ciphers and realtime communications?

Well, I finally did my duty and picked up a copy of Applied Cryptography. :)
I've only given it a cursory browing so far, but I have a question.
 
When I first saw reference to stream ciphers in the book, I imagined that they would be ideal for realtime encrypted communications, like voice (in cellular phones, perhaps).
But after reading further, it appears that stream ciphers aren't being used much
in this manner, or much at all.
Is this correct? I know that there are plenty of encryption protocols and methods for
realtime communications (clipper chip, for one), but do they just use block
ciphers with relatively small blocks? (Is the security of such things as RSA
and IDEA effected by size of block? There's got to be a minimum block that works;
you can't do IDEA on a single byte, or can you?)
 
Can anyone outline what kinds of methods are used for voice encryption and other realtime
methods, as contrasted with email and delayed transfer methods?

Stream ciphers are very efficient in hardware encryption applications, but
suck eggs in software.  They have been the workhorse of military cryptography
for at least 40 years, but those are all hardware applications.  If you
are working in software, it is much easier to deal with data in 64-bit
blocks than in individual bits.  The Shrinking Generator, which has only
two LFSRs, is slower than DES in software.  You need to iterate the
Shrinking Generator 64 times to encrypt the data that DES handles in just
one iteration.

Bruce