Electrical

• Mini-ISO Relays, like the ubiquitous Bosch 30A relays.
• Micro-ISO Relays, which are much more compact and better suited to motorcycle applications.
• Waterproofing Switches, since the last thing you want is for your heated grips to fail from a corroded switch.
• OEM-style Connectors, so your work on the wiring harness won't look butchered.

Resources

The Airhead BMW page has a ton of great information on relays.