Coffee grounds have a zero nutritional value, but they are highly acidic and could help slightly reduce you soil's pH.
That's it as far as I know.

George, that's not quite right :-) UCG's (used coffee grounds) do have a measurable nutrient content - approximately 2.1-0.3-0.3. True, not very high but then no organic nutrient source offers very high concentrations of nutrients and UCG's rate quite a bit higher in N than does compost.

And contrary to common belief, UCG's are not highly acidic. In fact, they are nearly neutral in pH - the acidity is in the liquid coffee itself. Grounds from espresso tend to be even less acidic than those from regular perked or drip coffee - the pressurized nature of the espresso process leaches out more acidity. That's why espresso is so much stronger than drip coffee. There are many threads discussing the value and use of UCG's on both the Soils/Compost and Organic Gardening forums if one wants to do further research.

An application of UCG's won't hurt and can help, just as any organic mulch can and does help soil conditioning and plant growth. The recommendation is to work them into the soil as they form a crust if allowed to dry out and repel water, much like peat moss can if allowed to dry. And fwiw, they are an excellent slug and snail deterrent.

Pam, thanks for correction.
Live and learn :-)