Hello, everyone.
I've just found out how to nudge, and also how to control grid values and nudge values from a macbook keyboard. (ctrl+opt+plus and ctrl+cmd+minus)
First of all, you have to download keyremap4macbook. It will also help you with the numpad commands such as 3 for punch in, 7 for metronome, using the fn key.
But it doesn't cover the keypad plus and minus signs (althought it says it does).
Afterwards, you have to create a custom XML configuration file so you can type fn+plus sign on the keyboard and it will remap it to the keypad plus sign, which is the one that triggers nudge related functions.
Here's an example, althought it maybe different in other keyboards, since my keyboard is spanish.
After you've created the xml file, in keyremap you can load the xml file and the new configurations will show up on top. No need for a external keypad.
<?xml version="1.0"?>
<root>
<item>
<name>Fn Keyboard + to Keypad +</name>
<identifier>private.swap_keyplus_and_keypadplus</identifier>
<autogen>__KeyToKey__ KeyCode::BRACKET_RIGHT, ModifierFlag::FN, KeyCode::KEYPAD_PLUS</autogen>
</item>
<item>
<name>Fn Keyboard - to Keypad -</name>
<identifier>private.swap_keyminus_and_keypadminu s</identifier>
<autogen>__KeyToKey__ KeyCode::SLASH, ModifierFlag::FN, KeyCode::KEYPAD_MINUS</autogen>
</item>
</root>
Hope it helps!