Seaweed seems to play an important role in the (hopefuly not so far) sustainable future. Different companies are trying to develop packaging products made of it. Seaweed has the potential to replace practically all plastic packaging. One of those companies is Noriware. They have developped a "plastic film" made 100% of organic materials. Have a look on their website to find out more.
A German based company "leaf republic" used to produce single use plates out of leaves which is a great environmentally friendly alternative to single use plastic. There are currently plates made of palm leaf, bamboo leaf, banana leaf, sugarcane, grass,.. So next time you are planning a party or for your stand at the next food festival look for plates that are biodegradable.
The advantage of plates made of leaves is that those leaves would normally rot unused anyway. By using them as plates no trees need to be cut and no chemicals are used that can harm the environment and less energy is needed because the material doesn't have to be produced first which is lowering its carbon footprint.
Probably the main part of its CO2 footprint comes from its transportation so if possible try find "leaf plates" who were produced near to your location. Check out following links for additional info on the topic.