Niven is a frequent collaborator; see his other contributions under Niven w/J. Pournelle, Niven w/EM Lerner, Niven w/S. Barnes, Niven w/Pournell, Flynn and Niven w/GC Johnson.

Gravity Lens - see the stars
An optical lens created using the lightbending properties of gravity.

Protector (1973)

Gravity Planer
Device that creates a gravity field.

The Warriors (1966)

Gravity-assisted Subway - the shortest possible distance
The fastest way between continents (that does not entail leaving the ground).

A World Out of Time (1976)

Holo
Abbreviation of "hologram".

Ringworld (1970)

Implant-Watch - this is so cool
Subcutaneous timepiece; uses patterns of colored lights to show the time.

Cloak of Anarchy (1972)

Inflatable Expansion Bubble - temporary room for space craft
Inflatable chamber to provide temporary additional space for cramped space craft.

Crashlander (1994)

Kemplerer (Klemperer) Rosette - planets without a sun
Planets without a sun; they orbit a central point.

Ringworld (1970)

Key Club - by booth id only
A social club made exclusive by teleportation booth; may be in a chain with other physically identical locations.

Flash Crowd (1972)

King's Free Park - a long narrow park
A park in which anarchy reigned; a very long, narrow park.

Cloak of Anarchy (1972)

Kzinti Lesson - Propulsion As Weapon
The power of a craft's means of propulsion repurposed as an offensive weapon.

The Warriors (1966)

Laser Cannon - ground-based power for space craft
A laser source powerful enough to provide significant light pressure to a "light sail."

Neutron Star (1966)

Launching Laser - power your craft with light
A set of very high-powered lasers used to power spacecraft.

The Fourth Profession (1971)

Light-Sword - not an epee
A laser tuned for use as a cutting tool.

Ringworld (1970)

Mass Pointer
Tells you where the really large (star-sized) masses are while you travel in hyperspace.

Crashlander (1994)

Membrane Balloon Helmet
A selectively permeable membrane worn as a helmet.

The Flight of the Horse (1969)

Memory Plastic
Takes various shapes impressed into it on command.

Death by Ecstasy (1969)

Mercy Rifle
Device fired slivers of anesthetic as darts.

Grendel (1968)

Microwave Beamer
A hand-held fast cooking device.

Limits (1985)

Mining Worm (Organic) - living miners
Genetically altered earthworm created just for mining.

A Gift From Earth (1968)

Monobloc Dating System - advanced dating software
A kind of pub with unique hardware and software for computer dating.

The Best of all Possible Wars (1998)