Is there any circuits I can do with this transistor?

[Purplebuttcheese]

The only markings it has is "DB SS PI 51" on the top and "6846 2N2858" on the side. Here's some pictures I took
http://m.imgur.com/a/I3sgJ

[Digital Larry]

Looks like a Silicon NPN with a minimum beta of 20!  which is really low.

http://alltransistors.com/transistor.php?transistor=2504

Fuzz circuits seem to like lower betas, but I'm used to seeing people talk about 50, 60, 70 range.  20 is just the minimum beta and who knows what it is really without measuring it.

[Kipper4]

Low hfe. Diy Darlington.
Or use as a body diode for clipping.

[antonis]

Excellent choice for current-pass transistor of a stabilized power supply..

[mac]

hfe>20, so it could be higher, in the right place 
Besides, it has a low ft compared to another low hfe transistors.
If you can, try to measure hfe.

mac

[Kipper4]

Good to see you around Mac.

[mac]

Good to see you around Mac.

I'll be back Rich

For example, TIPxx datasheet say hfe>15-20, around 60 typical.
I bet this is the case, so it could be used in FF, TB and other old fuzzes.

mac