Another option if you want to just try fruit without committing to a full keg is to put a bit of fruit puree in the glass prior to pouring (it might take a bit of a stir). You can make your own (either straight-up, or thinned out and sweetened with a bit of simple syrup), or use one of the commercially available craft purees. I like the Amoretti ones, because they have a pump, so you don't have to use the whole bottle all at once. They're a *touch* pricey, but quite worth the money, in my opinion. Their blood orange craft puree is pretty tasty, as is their peach puree (which I used to make an absolutely excellent peach IPA last summer). You can also mix them with sparkling water, etc., so there's versatility, too.
In any case, I'm a big fan of "add a shot of fruit by the glass", especially when experimenting with recipe.