Just an idea:
The simplest possible feature how a Stellar cryptocurrency could be useful on this very forum would be to have a "tip jar" feature, allowing users to donate XLM to each other for helpful posts.
The simplest way to implement this would be a small "tip jar" icon shown behind author names in Discourse posts. Hovering over the icon would show a tooltip "You can click to tip XLM if this post helped you." Clicking on the icon would open a URL that allows to send XLM to a pre-defined sender easily. (Not sure if that feature exists with Stellarterm or similar – probably yes, but did not check.)
In a Discourse-based website where I am involved as an admin, we did a similar thing with a small custom-made plugin – not exactly for a tipping URL, but for a profile reference URL to user accounts on our "moneyless" payment platform PayCoupons. You can see this in action in this post – watch out for the PayCoupons icon behind my username. The user enters the relevant username into a Discourse custom field in their profile. In the case of a tip jar, it would be a Stellar account ID instead. The code for this is open source and can be found in this plugin (that plugin contains all our custom Discourse mods, but pretty easy to separate).
Another option to implement this would be to find a tipping web service that supports Stellar Lumens (does that exist?) and then adapt the changetip-discourse plugin to talk to that web service.