dweet.io is twitter for IoT, simple but very practical.
If you need to send data (and you don't care for privacy of data you are sending) then you can use dweet, and this could be super useful.
So here is a simple example of how I send data from OpenWrt devices to dweet cloud.
wget -O /dev/null "http://dweet.io/dweet/for/test?current=0.1&voltage=11&temp=33"
To check if your data has been received just use /follow url for your thing, for example https://dweet.io/follow/test