If the usual Go-Bag is bigger for your purposes, then try the SOTech's mini go bag... "Distinct tactical hybrid of the popular Go Bag and a waist bag allowing for shoulder/backpack use and waist pack carry. Made in the USA Allows for easy front access to med kits, breaching gear, and SERE kits. The padded shoulder strap gives great stability that other waist packs lack.

When used as a go bag, the Go Bag Mini can store in between seats as a tubular bag and the end pull handle gives a quick and easy pull-and-go capability. Double zippers are against the body to allow access to bag contents while walking or running without removing the bag from the body."