If you really want to go way out for something different, instead of using traditional pasta for those spaghetti dishes, here is what we sometimes do.
Cook up a Spaghetti Squash - available seasonably at most produce departments - then open it and scrape the insides out per the instructions which are usually on the skin.
Set that aside.
Cook some French-cut green beans until they are just past al'dente. Drain, then set aside.
Now combine the squash insides and the green beans until they are well mixed.
Treat them as you would any other spaghetti by adding sauces, cheese, etc.
This isn't a substitute for good old fashioned pasta, but it is much lower in calories and carbohydrates.
Let me know how you like it.