I am pleased to announce that I and ndalliard are (probably) the first bitcointalk members to open a dual-funded channel

We both compiled the latest master branch of c-lightning and added "experimental-dual-fund" to our config files. ndalliard was the founder, so I had to configure the
funder policy plugin which is not documented well, yet. My funder policy currently looks as follows.
lightning-cli funderupdate
{
"summary": "fixed (750000sat)",
"policy": "fixed",
"policy_mod": 750000,
"min_their_funding": "500000000msat",
"max_their_funding": "4294967295000msat",
"per_channel_min": "500000000msat",
"per_channel_max": "4294967295000msat",
"reserve_tank": "0msat",
"fuzz_percent": 0,
"fund_probability": 100
}
In short, my node contributes 750k satoshis to every incoming channel (as long as I have enough funds in the wallet and the founder supports dual-funding) if that channel is bigger than 500k satoshis. I will keep my contribution at zero for most of the time. If someone running c-lightning wants to open a channel with me, let me know in advance so that I can change it back and help you with setting-up dual-funding. It might become easier in the upcoming v0.10.1 update.