1. Preheat grill to medium-high heat, approximately 400°F.
2. While the grill heats, combine olive oil, vinegar, basil, oregano, garlic, salt, and red pepper flakes in a large bowl.
3. Once mixed, toss zucchini and bell peppers in the marinade, then place them on a plate or cutting board.
4. Once vegetables are coated and set aside, add pork loin to the marinade and let soak for 10 to 15 minutes.
5. Once vegetables and pork are marinated, skewer pork loin, zucchini, and bell peppers, alternating ingredients; repeat until 4 skewers are full.
6. Once skewers are ready, lightly oil the heated grill, and then place kabobs on the grill and cover.
7. Turn skewers occasionally for 10 to 13 minutes, or until the pork loin is nice and browned.
8. Once cooked, remove the skewers from the grill and let stand for 3 to 5 minutes.
9. Once the skewers have cooled slightly, serve 'em up!
