Why not go for a wander with your portable transmitting gear?
Normally you'd take a mast and some wire for the antenna.
But you don't have to.
Do some 'urban antenna foraging' instead. That is to use something already there as an antenna.
Take your transceiver, a wide-range antenna coupler and a small length of wire with a clip lead. Oh and a wire counterpoise might help also.
Walk around your neighbourhood looking for metal objects to clip on to. A local park, river bank or beach might be a good place to start. Fire up your rig, and see if you can load it up with the antenna coupler. You may be lucky or your may not. Tune the bands for activity. Maybe try some WSPR - you're almost certain to be picked up somewhere on a band like 7 MHz.
SSB and CW can also be successful. The video below shows results I had recently in my neighbourhood. Yes, I'm lucky, being right near the beach. But other places and things like fences and light poles also offer possibilities. If you try this please let us know your results in the comments below.
PS: As you saw, the above walk was fun but didn't give predictable results. More reliable performing portable antennas are covered in Hand-carried QRP Antennas. Available in electronic and paperback form (some countries) this well-reviewed book is a popular read amongst hams who go portable.