Mega bump, but figured this was the best place to share my idea for naming small fractions of BTC.  It may seem complicated, but I think that with practice, this could be a manageable system for both online AND offline payments.  

Given that this is a global currency, and the metric system is used by the majority of the population, we should stick to a metric prefix system, similar to other ideas here in this thread.  I've added a few "rules" to help standardize and simplify the system.

Like so:

1 BTC = 1 Bit
0.1 BTC = 1 Decibit/Dec (Optional)
0.01 BTC = 1 Centibit/Cent
0.001 BTC = 1 Millibit/Mil
0.000,001 BTC = 1 Microbit/Micro
0.000,000,01 BTC = 1 Satoshi

In another form:

1 Bit = 10 Decs
1 Dec = 100 Cents
1 Cent = 100 Mils
1 Mil = 1,000 Micros
1 Micro = 100 Satoshi

Rules:  

1) The smallest unit possible is generally used.  Anything over 1 BTC is generally referred to in decimal (e.g. 1.35 BTC = "One point three five Bits")

2) Trailing zeroes should be used when interpretation of units is ambiguous. (See examples below)

3) Commas are used to the right of the decimal point every three spaces to assist unit assignment

4) Avoid awkward prices (e.g. 1.500,004,80 BTC).  Even so, could be read as "1.5 Bits and 480 Satoshi"

With this, you can easily speak lower prices without talking in decimals all the time. Generally, the fewer non-zero numbers in a BTC price, the better.

Examples:

0.40 BTC = 4 Decs OR 40 Cents
0.45 BTC = 45 Cents
0.452 BTC = 452 Mils
0.002,500 BTC = 2500 Micros OR 0.002,5 = "Two and a half Mils"
0.087 BTC = 87 Mils
0.000,346 BTC = 346 Micros
0.000,049 BTC = 49 Micros
0.000,000,12 = 12 Satoshi
0.000,003,12 BTC = 312 Satoshi

Thoughts, suggestions, criticisms? Having just 8 decimal places instead of 9 makes it slightly less intuitive than it could be when dealing with hundreds of Satoshi, but it's no different than saying that $1.32 is 132 cents.