As we all know, BTC is way volatile. But it's also true that if today EUR/USD is 1.45 and tomorrow 1.40, your coffee will still cost 1 EUR if you are in Europe or 1 USD if you're in the States, unless one of them really bumps (which would mean either European or American economies had ruined) there's no change in the end-consumer prices due to currency fluctuation.

So, for BTC we could come up with a simplified conversion table for people running business with it; something like:

BTC/USD low -   BTC/USD high  - Simplified conversion

0.10                    0.30                    0.25
0.30                    0.60                    0.50
0.60                    0.85                    0.75
0.85                    1.25                    1.00
1.25                    1.75                    1.50
1.75                    2.25                    2.00
2.25                    2.75                    2.50
2.75                    3.50                    3.00
3.50                    4.50                    4.00
4.50                    5.50                    5.00
(...)

The use of a simplified table will not stop fluctuation, but will help on stabilization.