Memo now supports exchanging SLP tokens! This is done using a decentralized trust-less protocol. See the specification on Github for more info.
This is a new feature that still has limited functionality. Beware there may be bugs or missing features, so use at your own risk.
Create your own listing to get started. There is a 1.5% fee on token exchanges.
After you create a listing people can make offers.
A few known issues to look out for:
1) Once an offer is submitted there is not yet a way to cancel it.
2) Offers are based on UTXOs. If a UTXO that was part of an offer is spent the offer is invalidated.