Just found out that you can have multiple wallets on ledger nano s.
You can add a passphrase to you 24 word seed The passphrase is like a 25th word on your 24 words seed, but one that you should remember and never write down. It scrambles your seed and generates a new identity: there is no right or wrong passphrase, each one will always derive a unique seed and set of accounts. (Personally i recomend saving this somewhare physical just like the seed)
Options
There are two options you can have a second wallet that is linked to a pin, so when you first plug in the nano you have a second pin that will open another wallet.
The second option is to open temporary wallets.
Second pin wallet.
Make sure you have Nano S 1.3 firmware updates.
You can't set a third PIN code. If you ever set a new PIN code attached to a passphrase, it would erase the first one.
Open the "Settings" of the Nano S
Select "Security"
Select "Passphrase"
Select "Attach to a PIN"
Enter a second and new PIN code
Confirm this new code
Enter and confirm a secret passphrase (100 characters max)
Enter your first main PIN code to validate
Temporary wallets
This you have to do every time you need to use this wallet type.
Open the "Settings" of the Nano S
Select "Security"
Select "Passphrase"
Select "Set temporary"
Enter and confirm your secret passphrase (100 characters max)
Enter your PIN code to validate
How to recover the hidden wallets
On your Nano S, just recover your 24 words and set your previous hidden passphrase as a temporary passphrase or as a hidden wallet attached to a PIN code.
Souceses
http://support.ledgerwallet.com/knowledge_base/topics/advanced-passphrase-options
http://support.ledgerwallet.com/knowledge_base/topics/how-to-recover-a-hidden-wallet
https://ledger.groovehq.com/knowledge_base/topics/how-to-setup-a-passphrase-and-an-alternate-pin