Axis and Allies with TWO boards!!!
My suggestion is very similar to Scott's, but with subtle variations to make it less burdensome to play in person.

This isn't a rule, just a suggestion: Play with someone you trust. There's going to be hidden information, and if you think the other player is going to cheat you're going to be paranoid about looking for malfeasance and not have fun. Two honest players can make this work without a moderator, which I think is important.

Two boards, one for the axis and one for the allies. If multiple players  represent each side then they see their side's board; this models the sharing of intelligence amongst friends and reduces the need for more than two boards. The boards should be set up in full view of both players and then a divider put up between then. After setup, the army trays and money are set to the side in view of both players so that it's clear what's going into and coming out of the trays (doveryai, no proveryai). Having the players in two rooms would be a logistical nightmare; this is simpler.

Each player can see units in enemy-controlled adjacent land territories. The friendly territory only has to be controlled, not occupied. This models the ability to generally know what the enemy has on the front lines and eliminates the need to add a new surveillance mechanic to the game. (The bomber idea sounds cool but would be tedious and error-prone in practice. Imagine the time spend reading off all the locations you wanted to spy on and then adjusting the board--at the start of every turn).

You cannot see adjacent naval territories. This models the largeness of the sea and difficulty of conducting naval reconnaissance with WWII-era ships. The only way you know what is in a sea territory is if you try and move into it. This would require only a minor change to the current rules: all naval movements are combat movements, unless ships were moving into friendly-occupied sea zones.

Fighters and bombers can only conduct &quot;reconnaissance&quot; of sea zones if they attack. If aircraft attack an occupied sea zone then combat commences as normal; if it is empty then their movement is consumed, but nothing else happens. Overflying a sea zone reveals nothing; you must commit to attack it. This models that searching the sea for ships is harder than overflying territory on your way somewhere else.
I like that this is similar to the original idea of using planes for spying but with less overhead. I also like that this enables submarines to become a more effective naval unit because they can &quot;hide&quot; in plain sight. An enemy has to use a fighter's attack to even see if they are there. I get excited thinking if Germany could use this rule to build a North Atlantic navy under the UK's nose.

Purchases are public knowledge; placement is not. Players must show their money and what they're buying. Purchases are placed in view of both players while the rest of the turn is conducted. This models the ability of nation to get a general idea of their enemies industrial capacity and capabilities. This also has the added benefit of reducing the opportunity to cheat because both players are verifying the amount of money being turned in and the units being purchased. (Also, honest math mistakes in purchasing are common.) Units are placed in secret, except for those placed on the front lines.


With these changes I think it would be possible to play with only two boards, in a single room, without a moderator. If anyone can think of any holes let me know.