Assuming a US citizen/resident, you'd still pay taxes at the federal level. You MIGHT qualify for a foreign earned income exclusion IF the income is under a certain level (all) and if it is over (part). Additionally, you may be eligible for a foreign tax credit if you pay taxes to a foreign government and there is a tax treaty in place (does not exist for every country).

NOTE - by being a "nomad," you have abandoned your tax home, and now ALL of your travel expenses, food, food, and lodging are NOT DEDUCIBLE for tax purposes.

From a state point of view, this will vary depending on the state. I guess the state where you hold a driver's license - vote will attempt to tax you on EVERYTHING. This is a guess. I know Michigan would try based on a Michigan driver's license. I'd assume that every other state would do the same.

NOTE - this can quickly become very complicated and is termed a "facts and circumstances" situation. Thus, this answer is NOT accurate for any specific situation. Instead, it is a general guideline for starting a conversation with competent tax counsel. Also, note that this WILL substantially increase the cost of your tax returns. Most likely more than four digits. NOT simple.